+publisher:"University of Michigan" +contributor:("Boehman, Andre L.")

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University of Michigan

1. Maldonado Puente, Bryan. Stochastic Analysis and Control of EGR-Diluted Combustion in Spark Ignition Engines at Nominal and Misfire-Limited Conditions.

Degree: PhD, Mechanical Engineering, 2019, University of Michigan

URL: http://hdl.handle.net/2027.42/153464

► Worldwide regulations on greenhouse gas emissions demand a reduction in fuel consumption from the transportation sector. This reduction requires incremental improvements in engine and powertrain… (more)

▼ Worldwide regulations on greenhouse gas emissions demand a reduction in fuel consumption from the transportation sector. This reduction requires incremental improvements in engine and powertrain efficiency. Feedback combustion control under diluted conditions with exhaust gas recirculation (EGR) has the potential to improve the overall efficiency of spark-ignition engines by optimizing combustion efficiency, reducing heat transfer losses, and reducing pumping losses at medium loads. This control problem requires the coordinated action of the EGR valve and the spark advance. However, cycle-to-cycle variability in the combustion process limits the closed-loop system performance. Moreover, the input-to-output coupling between the actuators and measured combustion features need to be addressed in the control design to avoid undesired combustion events such as knock, partially burned cycles, and misfires. Therefore, the combustion control problem at high EGR-diluted conditions is a constrained multivariable stochastic control problem. This dissertation focuses on the control of the spark advance and the EGR valve in order to maximize the EGR benefits while maintaining stable combustion during steady state and load transients. For a fixed engine speed/load condition, a two-input two-output discrete-time dynamic system was derived from system identification in order to use model-based control techniques. In particular, a linear quadratic Gaussian (LQG) controller was designed and experimentally tested for controlling spark and EGR valve. Such a controller was able to achieve an optimal combustion shape that maximizes EGR benefits and proved to be superior compared to traditional proportional-integral (PI) control strategies. An analytic solution for the amount of variability that the LQG controller contributes during closed-loop operation was derived, which can be used to modify the combustion targets to avoid misfire events. Given that sporadic misfires can occur when the control targets high levels of EGR, a stochastic controller based on the likelihood ratio test has been proposed to adjust the likelihood of misfires. When the engine speed is fixed and the load demand is controlled by the driver, the feedback combustion controller needs to react to such disturbance and maintain an optimal phasing. A physics-based model derived from manifold filling dynamics was coupled with a simple combustion model to formulate a three-input two-output dynamic system that considers not only the impact of the EGR valve and spark advance on the combustion, but also considers throttle tip-in and tip-out commands. The retuned LQG controller was experimentally tested and successfully maintained optimal phasing and maximized EGR levels during tip-in commands. However, during throttle tip-outs the system transitions through conditions where misfires occur. An explicit reference governor was designed to slow down the tip-out commands in order to avoid fast transitions that drive the system over the misfire limit. Given the inability to model… Advisors/Committee Members: Stefanopoulou, Anna G (committee member), Kolmanovsky, Ilya Vladimir (committee member), Boehman, Andre L (committee member), Freudenberg, James S (committee member).

Subjects/Keywords: Combustion Control; Internal Combustion Engines; Mechanical Engineering; Engineering

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APA (6^th Edition):

Maldonado Puente, B. (2019). Stochastic Analysis and Control of EGR-Diluted Combustion in Spark Ignition Engines at Nominal and Misfire-Limited Conditions. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/153464

Chicago Manual of Style (16^th Edition):

Maldonado Puente, Bryan. “Stochastic Analysis and Control of EGR-Diluted Combustion in Spark Ignition Engines at Nominal and Misfire-Limited Conditions.” 2019. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/153464.

MLA Handbook (7^th Edition):

Maldonado Puente, Bryan. “Stochastic Analysis and Control of EGR-Diluted Combustion in Spark Ignition Engines at Nominal and Misfire-Limited Conditions.” 2019. Web. 13 Apr 2021.

Vancouver:

Maldonado Puente B. Stochastic Analysis and Control of EGR-Diluted Combustion in Spark Ignition Engines at Nominal and Misfire-Limited Conditions. [Internet] [Doctoral dissertation]. University of Michigan; 2019. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/153464.

Council of Science Editors:

Maldonado Puente B. Stochastic Analysis and Control of EGR-Diluted Combustion in Spark Ignition Engines at Nominal and Misfire-Limited Conditions. [Doctoral Dissertation]. University of Michigan; 2019. Available from: http://hdl.handle.net/2027.42/153464

University of Michigan

2. Yoo, Kwang Hee. Effects of Gasoline Composition on Compression Ignition in a Motored Engine.

Degree: PhD, Mechanical Engineering, 2020, University of Michigan

URL: http://hdl.handle.net/2027.42/155275

► This study presents a fundamental investigation of gasoline autoignition behavior in a compression ignition engine, which is of great importance for next generation engine designs… (more)

▼ This study presents a fundamental investigation of gasoline autoignition behavior in a compression ignition engine, which is of great importance for next generation engine designs that employ low temperature combustion strategies. A total of eleven full boiling range gasolines with different octane number and sensitivity have been tested in a motored engine and a constant volume combustion chamber at various pressures, temperatures, and oxygen concentrations. For quantification of intermediate temperature heat release (ITHR), a new method was applied to the engine data by examining the maximum value of the second derivative of heat release rate. Combustion phasing comparisons of single-stage ignition fuels with various octane sensitivity showed that fuel with less octane sensitivity became more reactive as intake temperature and simulated exhaust gas recirculation (EGR) ratio decreased, while fuel with higher octane sensitivity had a reverse trend. When low temperature heat release (LTHR) was not active, the amount of ITHR increased as the intake temperature and oxygen mole fraction increased. These ITHR trends, depending on octane sensitivity, were almost identical with the trends of combustion phasing, showing that ITHR significantly affects fuel autoignition reactivity and determines octane sensitivity. In addition, the strong dependence of ITHR on equivalence ratio enhanced the ϕ-sensitivity. For the similar combustion phasing, the higher octane sensitivity fuels exhibited faster rise rates of ITHR intensity than the lower octane sensitivity fuels, leading to more advanced hot-ignition phasing with increasing equivalence ratio. For two-stage ignition fuels, LTHR significantly enhanced ITHR, eventually advancing the autoignition timing. Both LTHR and ITHR were suppressed by increasing the simulated EGR ratio. The intake pressure boosting increased LTHR whereas the magnitude of ITHR for fuels with a lower research octane number (RON), which exhibited a great amount of ITHR, became saturated as the intake pressure increased. However, the average ITHR per crank angle increased with the intake pressure, showing concise and strong intermediate temperature reaction. With regard to physical property effects, higher aromatic content led to lower volatility and higher density, resulting in a slower liquid fuel evaporation process. The physical ignition delay was very sensitive to air temperature whereas oxygen dilution rarely affected the physical ignition delay. With regard to chemical property effects at the same RON, fuel with a higher aromatic content was more resistant to autoignite at high pressure and less sensitive to the oxygen dilution whereas the alkane-rich fuel was less sensitive to the temperature due to pronounced negative temperature coefficient (NTC) behavior. For the same RON and octane sensitivity, fuel with a higher amount of n-alkane was less sensitive to the oxygen dilution. Advisors/Committee Members: Boehman, Andre L (committee member), Raman, Venkatramanan (committee member), Hoard, John W (committee member), Wooldridge, Margaret S (committee member).

Subjects/Keywords: Intermediate Temperature Heat Release; Octane Sensitivity; Gasoline Compression Ignition; FACE Gasoline; Ignition Delay; Autoignition; Mechanical Engineering; Engineering

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APA (6^th Edition):

Yoo, K. H. (2020). Effects of Gasoline Composition on Compression Ignition in a Motored Engine. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/155275

Chicago Manual of Style (16^th Edition):

Yoo, Kwang Hee. “Effects of Gasoline Composition on Compression Ignition in a Motored Engine.” 2020. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/155275.

MLA Handbook (7^th Edition):

Yoo, Kwang Hee. “Effects of Gasoline Composition on Compression Ignition in a Motored Engine.” 2020. Web. 13 Apr 2021.

Vancouver:

Yoo KH. Effects of Gasoline Composition on Compression Ignition in a Motored Engine. [Internet] [Doctoral dissertation]. University of Michigan; 2020. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/155275.

Council of Science Editors:

Yoo KH. Effects of Gasoline Composition on Compression Ignition in a Motored Engine. [Doctoral Dissertation]. University of Michigan; 2020. Available from: http://hdl.handle.net/2027.42/155275

University of Michigan

3. Wang, Hao. Model Predictive Climate Control for Connected and Automated Vehicles.

Degree: PhD, Naval Architecture & Marine Engineering, 2019, University of Michigan

URL: http://hdl.handle.net/2027.42/153481

► Emerging connected and automated vehicle (CAV) technologies are improving vehicle safety and energy efficiency to the next level and creating unprecedented opportunities and challenges for… (more)

▼ Emerging connected and automated vehicle (CAV) technologies are improving vehicle safety and energy efficiency to the next level and creating unprecedented opportunities and challenges for the control and optimization of the vehicle systems. While previous studies have been focusing on improving the fuel efficiency via powertrain optimizations, vehicle thermal management and its interaction with powertrain control in hot and cold weather conditions have not been fully explored. For light-duty vehicles, the power used by the climate control system usually represents the most significant thermal load. It has been shown that the thermal load imposed by the climate control system may lead to dramatic vehicle range reduction, especially for the vehicles with electrified powertrains. Besides its noticeable impact on vehicle range reduction, the performance of the climate control system also has a direct influence on occupant comfort and customer satisfaction. Aiming at reducing the energy consumption and improving the occupant thermal comfort (OTC) level for the automotive climate control system, this dissertation takes air conditioning (A/C) system as an example and is dedicated to developing practical A/C management strategies for electrified vehicles. In particular, the proposed strategies leverage the predictive information enabled by the CAV technologies such as the traffic and weather predictions. There are three novel MPC-based A/C management strategies developed in this dissertation, the hierarchical optimization, the precision cooling strategy (PCS), and the combined energy and comfort optimization (CECO). They can be differentiated by their OTC assumptions, robustness considerations, and implementation complexities on the testing vehicle. In the hierarchical optimization, a two-layer hierarchical MPC (H-MPC) scheme is exploited for potential integration between the A/C and the powertrain systems of an HEV. This hierarchical structure handles the timescale difference between power and thermal systems as well as the uncertainties associated with long prediction horizon. Comprehensive simulation results over different driving cycles have demonstrated the energy saving potentials of efficient A/C energy management, which is attributes to leveraging the vehicle speed sensitivity of the A/C system efficiency. In terms of the comfort metric, the average cabin air temperature is applied. In contrast to this hierarchical optimization, PCS and CECO utilize the simpler single-layer MPC structure assuming accurate predictive information. They are focusing on formulating more practical OTC metrics and the implementation on the testing vehicle. Specifically, the PCS renders the simplest control-oriented model structure and its energy benefits are validated based on an industrial-level A/C system model. The proposed PCS exploits a more practical comfort metric, DACP, which directly motivates the design of an off-line eco-cooling strategy, which coordinates the A/C operation with respect to the vehicle speed. Vehicle-level… Advisors/Committee Members: Kolmanovsky, Ilya Vladimir (committee member), Sun, Jing (committee member), Boehman, Andre L (committee member), Hofmann, Heath (committee member).

Subjects/Keywords: model predictive climate control; connected and automated vehicle; energy and comfort optimization; vehicle thermal management; Naval Architecture and Marine Engineering; Engineering

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Wang, H. (2019). Model Predictive Climate Control for Connected and Automated Vehicles. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/153481

Chicago Manual of Style (16^th Edition):

Wang, Hao. “Model Predictive Climate Control for Connected and Automated Vehicles.” 2019. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/153481.

MLA Handbook (7^th Edition):

Wang, Hao. “Model Predictive Climate Control for Connected and Automated Vehicles.” 2019. Web. 13 Apr 2021.

Vancouver:

Wang H. Model Predictive Climate Control for Connected and Automated Vehicles. [Internet] [Doctoral dissertation]. University of Michigan; 2019. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/153481.

Council of Science Editors:

Wang H. Model Predictive Climate Control for Connected and Automated Vehicles. [Doctoral Dissertation]. University of Michigan; 2019. Available from: http://hdl.handle.net/2027.42/153481

University of Michigan

4. Alzahrani, Fahad. Theoretical and Experimental Study of Fuel Injector Tip Wetting as a Source of Particulate Emissions in Gasoline Direct-Injection Engines.

Degree: PhD, Mechanical Engineering, 2019, University of Michigan

URL: http://hdl.handle.net/2027.42/155041

► Gasoline fuel film deposited on the tip of a fuel injector, i.e. injector tip wetting, has been identified as a significant source of particulate emissions… (more)

▼ Gasoline fuel film deposited on the tip of a fuel injector, i.e. injector tip wetting, has been identified as a significant source of particulate emissions at some operating conditions of gasoline direct-injection engines. The liquid film on the injector tip can be reduced by either mitigating the initial fuel film that deposits on the tip during injection or by evaporating all or most of the fuel film before ignition takes place. The former process requires a clear understanding of the dependence of the fuel film formation on injector design, operating conditions and fuel flow conditions through the injector nozzle, which impose difficulties in the understanding due to the complex and interrelated processes involved. The liquid film evaporation process, i.e. injector tip drying, however depends mainly on engine operating conditions, and less on hardware or fuel flow dynamics. Understanding of the physics of injector tip drying is therefore less ambiguous but remains a challenge. Clear understanding of the tip drying physics can lead to significant reductions in PN emissions due to tip wetting. This work developed an analytical model for liquid film evaporation on the injector tip during an engine cycle for the mitigation of injector tip wetting. The model explains theoretically how fuel films on the injector tip evaporate with time from end of injection to spark. The model takes into consideration engine operating conditions, such as engine speed, engine load, tip and fuel temperatures, gas temperature and pressure, and fuel properties. The model was able to explain for the first time the observed trends in particulate number (PN) emissions due to injector tip wetting at different operating conditions. Engine experiments were used to validate the theoretical model by correlating the film mass predicted at the time of spark to PN and tip deposit volume measurements at different conditions. A new experimental technique was developed to measure the volume of tip deposit for this purpose since tip deposits are good indicators of tip wetting. In addition, an evaporation time constant was defined and was also found to correlate well with measured PN for all conditions tested. Injector manufacturers can use this time constant to maximize liquid film evaporation by correlating the variables in the time constant equation to changes in hardware and calibration. The results indicate that the liquid film evaporation on the injector tip follows a first order, asymptotic behavior. Additionally, the initial film mass after end of injection was confirmed to increase linearly with the injected fuel mass, i.e. engine load. Furthermore, the observed increasing exponential trend in PN emissions with engine load was due to the exponential nature of injector tip drying. As the initial film mass after injection increased linearly with engine load, the film mass at the time of spark increased in an exponential manner. A parametric study was also performed to understand the influence of the different initial and boundary conditions on fuel… Advisors/Committee Members: Sick, Volker (committee member), Raman, Venkatramanan (committee member), Boehman, Andre L (committee member), Fatouraie, Mohammad (committee member).

Subjects/Keywords: injector tip wetting; injector tip drying; soot formation; gasoline; direct injection; modeling; Chemical Engineering; Engineering (General); Mechanical Engineering; Transportation; Chemistry; Mathematics; Natural Resources and Environment; Physics; Science (General); Statistics and Numeric Data; Engineering; Science

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APA (6^th Edition):

Alzahrani, F. (2019). Theoretical and Experimental Study of Fuel Injector Tip Wetting as a Source of Particulate Emissions in Gasoline Direct-Injection Engines. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/155041

Chicago Manual of Style (16^th Edition):

Alzahrani, Fahad. “Theoretical and Experimental Study of Fuel Injector Tip Wetting as a Source of Particulate Emissions in Gasoline Direct-Injection Engines.” 2019. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/155041.

MLA Handbook (7^th Edition):

Alzahrani, Fahad. “Theoretical and Experimental Study of Fuel Injector Tip Wetting as a Source of Particulate Emissions in Gasoline Direct-Injection Engines.” 2019. Web. 13 Apr 2021.

Vancouver:

Alzahrani F. Theoretical and Experimental Study of Fuel Injector Tip Wetting as a Source of Particulate Emissions in Gasoline Direct-Injection Engines. [Internet] [Doctoral dissertation]. University of Michigan; 2019. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/155041.

Council of Science Editors:

Alzahrani F. Theoretical and Experimental Study of Fuel Injector Tip Wetting as a Source of Particulate Emissions in Gasoline Direct-Injection Engines. [Doctoral Dissertation]. University of Michigan; 2019. Available from: http://hdl.handle.net/2027.42/155041

5. Kang, Dongil. Impacts of Fuel Chemical Structure and Composition on Fundamental Ignition Behavior and Autoignition Chemistry in a Motored Engine.

Degree: PhD, Chemical Engineering, 2016, University of Michigan

URL: http://hdl.handle.net/2027.42/133374

► The autoignition characteristics of individual hydrocarbon species studied in motored engine can provide a better understanding of the autoignition process and complex fuels for homogeneous… (more)

▼ The autoignition characteristics of individual hydrocarbon species studied in motored engine can provide a better understanding of the autoignition process and complex fuels for homogeneous spark and compression ignition engines, whether the interest is understanding and preventing knock or controlling autoignition. In both instances, there is a critical need to comprehend how fuel molecular structure either retards or promotes autoignition reactivity. This understanding ultimately contributes to the development of kinetic mechanisms, which are needed for simulation of reacting flows and autoignition processes. For this reason, the dissertation discusses autoignition data on i) three pentane isomers (n-pentane, neo-pentane and iso-pentane), ii) ethyl-cycloahexane and its two isomers (1,3-dimethyl-cyclohexane and 1,2-dimethyl-cyclohexane), and iii) diisobutylene in primary reference fuels. looking for their chemical structural impacts on the ignition process. Particularly for exploring the low and intermediate temperature regions, the motored variable compression ratio engine, developed from a Cooperative Fuel Research (CFR) Octane Rating engine, provided a good platform. Analyses of the stable intermediates in the CFR engine exhaust at various end of compression pressures and temperatures can help to identify reaction pathways through which different compounds prefer to autoignite. The approach of those studies is to conduct a systematic investigation of the autoignition, which can provide useful input for qualitative and semi-quantitative validation of kinetic mechanisms for oxidation of target chemical compounds. Finally, the dissertation is further extended to an experimental validation of jet aviation fuel surrogates, potentially emulating a series of physical and chemical ignition processes in diesel engines, with an emphasis on the needs for detailed auto-ignition characteristics of various individual hydrocarbon species. Advisors/Committee Members: Boehman, Andre L (committee member), Savage, Phillip E (committee member), Violi, Angela (committee member), Schwank, Johannes W (committee member).

Subjects/Keywords: Autoignition process; CFR octane rating engine; hydrocarbon oxidation; Chemical Engineering; Mechanical Engineering; Engineering

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APA (6^th Edition):

Kang, D. (2016). Impacts of Fuel Chemical Structure and Composition on Fundamental Ignition Behavior and Autoignition Chemistry in a Motored Engine. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/133374

Chicago Manual of Style (16^th Edition):

Kang, Dongil. “Impacts of Fuel Chemical Structure and Composition on Fundamental Ignition Behavior and Autoignition Chemistry in a Motored Engine.” 2016. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/133374.

MLA Handbook (7^th Edition):

Kang, Dongil. “Impacts of Fuel Chemical Structure and Composition on Fundamental Ignition Behavior and Autoignition Chemistry in a Motored Engine.” 2016. Web. 13 Apr 2021.

Vancouver:

Kang D. Impacts of Fuel Chemical Structure and Composition on Fundamental Ignition Behavior and Autoignition Chemistry in a Motored Engine. [Internet] [Doctoral dissertation]. University of Michigan; 2016. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/133374.

Council of Science Editors:

Kang D. Impacts of Fuel Chemical Structure and Composition on Fundamental Ignition Behavior and Autoignition Chemistry in a Motored Engine. [Doctoral Dissertation]. University of Michigan; 2016. Available from: http://hdl.handle.net/2027.42/133374

University of Michigan

6. Assanis, Dimitris. Computational and Experimental Development of Novel Combustion Strategies for Advanced Internal Combustion Engines.

Degree: PhD, Mechanical Engineering, 2016, University of Michigan

URL: http://hdl.handle.net/2027.42/135834

► Fuel lean combustion strategies are attractive methods to increase the thermal efficiency of gasoline, spark ignition, internal combustion engines, but engine design remains challenging due… (more)

▼ Fuel lean combustion strategies are attractive methods to increase the thermal efficiency of gasoline, spark ignition, internal combustion engines, but engine design remains challenging due to the lean flammability limits of the fuel/air mixture. Turbulent jet ignition originating from a pre-chamber can help address mixture flammability limits by ejecting high enthalpy and highly reactive jets into the main combustion chamber, enabling overall lean combustion. Appropriate mixture conditions must be achieved in the main combustion chamber as well as in the pre-chamber for this strategy to be successful. This dissertation study considered a series of experimental and computational efforts to support the development of lean burn reciprocating engines. Fundamental combustion experiments to quantify flame speeds, flammability limits, and the interaction between flames and auto-ignition events of lean iso-octane /air mixtures were performed at premixed, moderate temperature and pressure conditions in a rapid compression facility. The results provided the first measurements of lean flammability limits at conditions relevant to spark ignition engines. Next, computational fluid dynamics was used to evaluate six prototype engine configurations with the goal of achieving ignitable, near-stoichiometric, fuel-to-air equivalence ratios in two indirectly fueled pre-chambers, while simultaneously achieving fuel lean equivalence ratios in the main combustion chamber. The simulation results showed the final iteration achieved the design goals with good flexibility in the fuel injection strategies. In the next stage of the project, optically accessible engine hardware was produced based on the CFD results to evaluate the fuel and air flow motion. High speed cinematography and pressure diagnostics were used with a fully-transparent cylinder liner to illuminate and image the fuel spray and air charge motion using Mie scattering. The fuel flow motion was in agreement with CFD predictions and the air charge imaging confirmed vortices were developed near the surface of the piston. The fuel spray data are the first in situ measurements of the unique fueling strategy and unique hardware. The combination of fundamental experiments, computational studies and applied experimental validations have demonstrated a new process and new outcomes for combustion science and technology that can operate significantly more fuel lean than traditional spark ignition engines. Advisors/Committee Members: Wooldridge, Margaret S (committee member), Adriaens, Peter (committee member), Boehman, Andre L (committee member), Papalambros, Panos Y (committee member).

Subjects/Keywords: This dissertation study considered a series of experimental and computational efforts to support the development of lean burn reciprocating engines.; turbulent jet ignition torch ignition; lean burn gasoline spark ignition engine; Mechanical Engineering; Transportation; Engineering

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Assanis, D. (2016). Computational and Experimental Development of Novel Combustion Strategies for Advanced Internal Combustion Engines. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/135834

Chicago Manual of Style (16^th Edition):

Assanis, Dimitris. “Computational and Experimental Development of Novel Combustion Strategies for Advanced Internal Combustion Engines.” 2016. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/135834.

MLA Handbook (7^th Edition):

Assanis, Dimitris. “Computational and Experimental Development of Novel Combustion Strategies for Advanced Internal Combustion Engines.” 2016. Web. 13 Apr 2021.

Vancouver:

Assanis D. Computational and Experimental Development of Novel Combustion Strategies for Advanced Internal Combustion Engines. [Internet] [Doctoral dissertation]. University of Michigan; 2016. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/135834.

Council of Science Editors:

Assanis D. Computational and Experimental Development of Novel Combustion Strategies for Advanced Internal Combustion Engines. [Doctoral Dissertation]. University of Michigan; 2016. Available from: http://hdl.handle.net/2027.42/135834

7. Wagnon, Scott William. Chemical Kinetics for Advanced Combustion Strategies.

Degree: PhD, Mechanical Engineering, 2014, University of Michigan

URL: http://hdl.handle.net/2027.42/108943

► This dissertation presents new understanding of the role of fuel chemistry on reaction pathways important to fuel oxidation and ignition at conditions relevant to advanced… (more)

▼ This dissertation presents new understanding of the role of fuel chemistry on reaction pathways important to fuel oxidation and ignition at conditions relevant to advanced combustion strategies. A deeper and quantitative understanding of fuel chemistry effects on combustion behavior can be used to improve modern combustion strategies that operate at low temperature (<1200 K) conditions using conventional or alternative fuels. A comprehensive understanding of the role of fuel chemistry enables high efficiency and low emissions from combustion technologies. This work used experimental and computational studies to understand the impact of fuel chemistry at low temperature conditions that are the focus of modern combustion systems. Optically accessible facilities, including a rapid compression machine and a shock tube, were used to study global and detailed combustion chemistry of several important fuel compounds. The results of the computational study on buffer gas composition effects on fuel ignition indicated that ignition phasing is sensitive to composition effects at low pressures, high levels of dilution, and temperatures corresponding to non-Arrhenius or multi-stage conditions. The results of the work on ignition behavior of methyl trans-3-hexenoate highlighted uncertainties in unsaturated methyl ester reaction chemistry, namely the R+O2 reaction rates and products of smaller unsaturated intermediates. The data presented in the phenyl oxidation study are the first laser schlieren measurements of radical oxidation reactions and the results provide a foundation for further studies which quantify important elementary reaction rates and pathways in oxidation systems, such as phenyl+O2. In the work with the three linear hexene isomers, the length of the alkyl chain was responsible for changes in reactivity, activation energy, and measured differentiation in the formation of stable intermediates at the conditions studied. The results of these studies quantify the reactivity of important fuel compounds, which is particularly vital as fuel feed stocks change and the low temperature operating conditions of modern combustion systems become more reaction limited. The results also inform theory on reaction rate rules for elementary reactions and guide the development of detailed, global, and skeletal reaction mechanisms at low temperatures. Advisors/Committee Members: Wooldridge, Margaret S. (committee member), Gamba, Mirko (committee member), Boehman, Andre L. (committee member), Violi, Angela (committee member), Tranter, Robert S. (committee member).

Subjects/Keywords: Alternative Fuels; Experimental Chemical Kinetics; Low Temperature Combustion; Rapid Compression Facility; Shock Tube; Mechanical Engineering; Engineering

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APA (6^th Edition):

Wagnon, S. W. (2014). Chemical Kinetics for Advanced Combustion Strategies. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/108943

Chicago Manual of Style (16^th Edition):

Wagnon, Scott William. “Chemical Kinetics for Advanced Combustion Strategies.” 2014. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/108943.

MLA Handbook (7^th Edition):

Wagnon, Scott William. “Chemical Kinetics for Advanced Combustion Strategies.” 2014. Web. 13 Apr 2021.

Vancouver:

Wagnon SW. Chemical Kinetics for Advanced Combustion Strategies. [Internet] [Doctoral dissertation]. University of Michigan; 2014. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/108943.

Council of Science Editors:

Wagnon SW. Chemical Kinetics for Advanced Combustion Strategies. [Doctoral Dissertation]. University of Michigan; 2014. Available from: http://hdl.handle.net/2027.42/108943

University of Michigan

8. Han, Tae Hoon. Strategies to Improve Efficiency and Emissions in Spark Ignition Engines.

Degree: PhD, Mechanical Engineering, 2019, University of Michigan

URL: http://hdl.handle.net/2027.42/153471

► This dissertation investigates the knock mitigation strategies and their experimental validation for improving performance and emissions with three different engine parameters: (i)Fuels (oxygenated fuel gasoline… (more)

▼ This dissertation investigates the knock mitigation strategies and their experimental validation for improving performance and emissions with three different engine parameters: (i)Fuels (oxygenated fuel gasoline blends and syngas addition); (ii)Mixture dilution (EGR and Lean dilution); (iii)Injection strategies (DI and PFI combined dual fuel injection and multiple injections). Besides, a newly discovered unique relation between knocking and particulate matter emissions is examined in the last part with several conceptual models for better understanding of this phenomenon. The first part of this dissertation is about the effects of three oxygenated fuels (2,5-dimethylfuran, ethanol, and isobutanol) blended in gasoline on engine combustion, knock, and particulate matter emissions. One of the most promising furan functional group fuels, 2,5-dimethylfuran, is experimentally compared with two common alcohol-type oxygenates, ethanol and iso-butanol. Three major parameters are varied for the examination of oxygenates: fuel type, blend ratio, and boost level. The results show that the 2,5-dimethylfuran blends have the ability to extend knock limits as much as ethanol, but with relatively higher particulate matter emissions. As a second fuel study, syngas (hydrogen and carbon monoxide) aided engine combustion is experimentally investigated under EGR diluted and lean conditions by focusing on knock propensity, thermal efficiency, and emissions. Knocking tendencies are analyzed, and the thermal efficiency and emissions difference are discussed as well. The results show that with increasing the syngas addition, knocking is strongly suppressed, and the effect is more beneficial with EGR dilution than with air dilution. For the study of fuel injection strategies, two concepts of injection strategies are introduced and experimentally investigated. The first injection strategy is combined direct and port fuel injection to extend knock and EGR dilution limits using gasoline and ethanol fuels. The results showed that dual injection was beneficial to shorten the burn duration and improve combustion stability, but dual injection is slightly more sensitive to knock than direct injection primarily due to increased unburned gas temperature. The particulate matter emissions from dual injection were slightly lower, and the gaseous emissions showed lower total hydrocarbons and similar nitrogen oxides compared with only using direct injection of E20 fuel. The second fuel injection strategy involves multiple direct injections, which inject fuel multiple times in a cycle. This study explores the effect of multiple injections on knock, engine performance, particulate matter, and gaseous emissions. Two aspects of multiple injection strategies were experimentally investigated: the number of injections and the timing of the injections. The results confirm that multiple injection maintains torque and combustion stability but increases knock limits and thermal efficiency due to improved heat release phasing. The gaseous pollutant emissions including… Advisors/Committee Members: Boehman, Andre L (committee member), Raman, Venkatramanan (committee member), Lavoie, George A (committee member), Wooldridge, Margaret S (committee member).

Subjects/Keywords: Knock limit extension; Particulate matter emissions; Exhaust Gas Recirculation (EGR); Alternative fuels; Injection strategies; Spark ignition (SI) engine; Mechanical Engineering; Engineering

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APA (6^th Edition):

Han, T. H. (2019). Strategies to Improve Efficiency and Emissions in Spark Ignition Engines. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/153471

Chicago Manual of Style (16^th Edition):

Han, Tae Hoon. “Strategies to Improve Efficiency and Emissions in Spark Ignition Engines.” 2019. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/153471.

MLA Handbook (7^th Edition):

Han, Tae Hoon. “Strategies to Improve Efficiency and Emissions in Spark Ignition Engines.” 2019. Web. 13 Apr 2021.

Vancouver:

Han TH. Strategies to Improve Efficiency and Emissions in Spark Ignition Engines. [Internet] [Doctoral dissertation]. University of Michigan; 2019. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/153471.

Council of Science Editors:

Han TH. Strategies to Improve Efficiency and Emissions in Spark Ignition Engines. [Doctoral Dissertation]. University of Michigan; 2019. Available from: http://hdl.handle.net/2027.42/153471

University of Michigan

9. Medina, Mario. Experimental Studies of High-pressure Gasoline Fuel Sprays for Advanced Internal Combustion Engines.

Degree: PhD, Mechanical Engineering, 2020, University of Michigan

URL: http://hdl.handle.net/2027.42/155095

► While much has been learned about gasoline direct injection sprays, there are still large gaps in the fundamental knowledge of the effects of high-pressure (over… (more)

▼ While much has been learned about gasoline direct injection sprays, there are still large gaps in the fundamental knowledge of the effects of high-pressure (over 500 bar) on gasoline sprays and on the role of fuel spray/nozzle interactions on particulate emissions. Particulate emissions are a critical concern for direct fuel injection spark-ignited engines, as future regulations may be difficult to meet without after-treatment. The objective of this dissertation was to quantitatively and qualitatively characterize fuel spray development for gasoline under engine-relevant conditions using non-intrusive optical techniques including high fuel injection pressures and canonical studies of the effects of internal flow structures on external spray development. Two experimental facilities were used to study high-pressure gasoline spray development and one experimental facility was used to study injector tip wetting and the effects on engine-out particulate emissions. Experiments were conducted at the University of Michigan with a constant volume chamber and diffuse backlit shadowgraph imaging for a range of chamber pressures (1 – 20 bar), injection pressures (300 – 1500 bar), and for several canonical fuel injector nozzle geometries including different nozzle exit diameters, converging and diverging nozzles, and rounded and abrupt inlet nozzles. The images were used to measure penetration distance and rate and spray angle as a function of time for each injection event, which are compared with results of previous experimental studies and simplified physics-based models that have been proposed in the literature. Trends in fuel spray development were similar to those observed previously for diesel sprays, which was unexpected given the significant differences in thermal-physical properties. Some abnormal spray features were identified and quantified, including spray flutter (i.e., asymmetric variation in spray angle). Injector internal flow characterization and spray development measurements were also performed at Centro Motores Termicos, an engine research division at the Universitat Politecnica de Valencia (UPV). Rate of injection, and momentum flux, were measured using two facilities and spray development was imaged using schlieren in another facility for a range of chamber pressures (5 – 30 bar), and injection pressures (600 – 1500 bar), and included vaporizing and non-vaporizing chamber temperatures of 400 – 800 K. The work revealed the important effect of internal flow transitions on injector performance, where nozzles with inlet rounding resulted in 20% higher mass flow rate compared with straight cylindrical nozzles. Spray momentum coefficients showed a negative trend with increased pressure differential indicating all nozzles were cavitating under all conditions tested. Lastly, trends in measured engine-out particulate number (PN) emissions were correlated as a function of a large array of fuel injectors, multiple engine architectures, and a large parametric space of operating conditions. PN was measured directly… Advisors/Committee Members: Wooldridge, Margaret S (committee member), Gamba, Mirko (committee member), Boehman, Andre L (committee member), Capecelatro, Jesse Samuel (committee member), Clack, Herek (committee member).

Subjects/Keywords: Fuel sprays; High pressure injection; Gasoline fuel; Mechanical Engineering; Transportation; Engineering

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APA (6^th Edition):

Medina, M. (2020). Experimental Studies of High-pressure Gasoline Fuel Sprays for Advanced Internal Combustion Engines. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/155095

Chicago Manual of Style (16^th Edition):

Medina, Mario. “Experimental Studies of High-pressure Gasoline Fuel Sprays for Advanced Internal Combustion Engines.” 2020. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/155095.

MLA Handbook (7^th Edition):

Medina, Mario. “Experimental Studies of High-pressure Gasoline Fuel Sprays for Advanced Internal Combustion Engines.” 2020. Web. 13 Apr 2021.

Vancouver:

Medina M. Experimental Studies of High-pressure Gasoline Fuel Sprays for Advanced Internal Combustion Engines. [Internet] [Doctoral dissertation]. University of Michigan; 2020. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/155095.

Council of Science Editors:

Medina M. Experimental Studies of High-pressure Gasoline Fuel Sprays for Advanced Internal Combustion Engines. [Doctoral Dissertation]. University of Michigan; 2020. Available from: http://hdl.handle.net/2027.42/155095

University of Michigan

10. Tibavinsky, Ivan. Thermal Emission of Strontium Products for Scalar Diagnostics in Internal Combustion Engines.

Degree: PhD, Mechanical Engineering, 2019, University of Michigan

URL: http://hdl.handle.net/2027.42/153368

► Developments in optical diagnostics for combustion systems have been essential to the recent improvements in efficiency and abatement of emissions that internal combustion engines have… (more)

▼ Developments in optical diagnostics for combustion systems have been essential to the recent improvements in efficiency and abatement of emissions that internal combustion engines have undergone recently. Great emphasis has been placed in the measurement of quantities with high temporal and spatial resolution, which has enabled the understanding of key physical and chemical processes, but there remains a need for obtaining spatially integrated measurements to understand how local events affect the overall behavior of the gases in a turbulent combustion chamber. Strontium offers a potential avenue to provide these measurements. When present in combustion it produces strontium monohydroxide, which spontaneously emits radiation in several bands of the visible spectrum, and thus enables the determination of temperature independently of species concentration through the Boltzmann distribution. Further, chemical equilibrium calculations can relate equivalence ratio to the relative concentration strontium and strontium monohydroxide, which could also be measured optically. The potential of this technique was explored in this work. An optical engine was operated under different conditions with a strontium-containing fuel and spectral measurements of the radiation emitted from the chamber were performed. The temperature in the cylinder was predicted by a one-dimensional thermodynamic model that used a two-zone model for flame propagation. The relative spectrally resolved emission intensity of atomic strontium and strontium monohydroxide was measured using a spectrometer coupled with camera, and the collected signals were related to the conditions in the chamber. From the results the mathematical formulation for the relationship of spectral intensity with temperature was found to be adequate, and important insights for the application of the diagnostic in imaging experiments were obtained. A universally applicable calibration was not attained due to experimental limitations, however, but the key barriers to overcome were identified. Advisors/Committee Members: Sick, Volker (committee member), Gamba, Mirko (committee member), Boehman, Andre L (committee member), Sangi Reddy, Pramod (committee member).

Subjects/Keywords: Engine optical diagnostics; Strontium spectral emission; strontium monohydroxide; internal combustion engines; Mechanical Engineering; Engineering

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APA (6^th Edition):

Tibavinsky, I. (2019). Thermal Emission of Strontium Products for Scalar Diagnostics in Internal Combustion Engines. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/153368

Chicago Manual of Style (16^th Edition):

Tibavinsky, Ivan. “Thermal Emission of Strontium Products for Scalar Diagnostics in Internal Combustion Engines.” 2019. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/153368.

MLA Handbook (7^th Edition):

Tibavinsky, Ivan. “Thermal Emission of Strontium Products for Scalar Diagnostics in Internal Combustion Engines.” 2019. Web. 13 Apr 2021.

Vancouver:

Tibavinsky I. Thermal Emission of Strontium Products for Scalar Diagnostics in Internal Combustion Engines. [Internet] [Doctoral dissertation]. University of Michigan; 2019. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/153368.

Council of Science Editors:

Tibavinsky I. Thermal Emission of Strontium Products for Scalar Diagnostics in Internal Combustion Engines. [Doctoral Dissertation]. University of Michigan; 2019. Available from: http://hdl.handle.net/2027.42/153368

University of Michigan

11. Sun, Chenxi. Nanostructure and Reactivity of Soot Produced from Partially Premixed Charge Compression Ignition (PCCI) Combustion and Post Injection.

Degree: PhD, Mechanical Engineering, 2017, University of Michigan

URL: http://hdl.handle.net/2027.42/140920

► Researchers have invested significant effort on optimizing the engine operation mode while cutting down the emissions due to increasingly strict emissions regulations. This study explores… (more)

▼ Researchers have invested significant effort on optimizing the engine operation mode while cutting down the emissions due to increasingly strict emissions regulations. This study explores Partially-Premixed Charge Compression Ignition (PCCI) combustion and post injection in a light duty multicylinder turbodiesel engine to reduce particulate matter (PM) and NOx emissions without sacrificing the engine performance. Three different fuels are tested in this PCCI combustion research: Ultra Low Sulfur Diesel (ULSD), diesel fuel produced via a low temperature Fischer-Tropsch process (LTFT) and a Renewable Diesel (RD). Late injection PCCI combustion can reduce NOx emissions by 76-78% and reduce soot emissions by 25-35%. High cetane number (CN), high ignition quality fuels LTFT and RD only increase CO emissions by 40-45% and THC emissions by 11-16% under late injection PCCI combustion compared to conventional combustion, while ULSD increases CO emissions by 78% and THC emissions by 24% under late injection PCCI combustion. The reaction rate constants of soot produced from late injection PCCI combustion are 1.2-2.2 times higher than soot from the conventional combustion conditions. The reaction rate constants of soot from LTFT and RD fuels are 47-66% lower than soot produced from ULSD. Soots produced from PCCI combustion have smaller graphene layers, higher surface oxygen concentration and higher portion of amorphous carbon. In addition, the primary particle and particle aggregate sizes are around 25nm and 400 nm for conventional combustion soot, while 10 nm and 150 nm for late injection PCCI combustion soot. Soots produced from LTFT and RD fuel under conventional combustion, show internal burning during oxidation. However, soots produced from late injection PCCI combustion and ULSD show shrinking core oxidation, likely because of their overall amorphous structure. Post injection is another method to reduce engine-out soot emissions while maintaining efficiency, potentially to reduce or eliminate exhaust aftertreatment. Close-coupled post injections reduce soot emissions by 11-21%, THC emissions by 14-28%, and CO emissions by 7-8%. However, NOx emissions increase by 3-5%. For long-dwell post injection condition, soot emissions are reduced by 28-33% and NOx emissions are reduced by 7-8%. CO and THC emissions do not vary much under long dwell post injection conditions. The reaction rate constants of soot from close-coupled post injection conditions increase by 10-13% compared to baseline condition, while the reaction rate constants of soot from long dwell post injection conditions decrease by 37-39% compared to baseline condition. Moreover, with the increase of injection dwell and post injection size, soot surface oxygen content and amorphous carbon content increase. This explains the change in reactivity of soot from different injection dwells. Primary soot particle and particle aggregate sizes do not vary much with post injection. Soot from post injection conditions all show shrinking core type oxidation without graphene… Advisors/Committee Members: Boehman, Andre L (committee member), Lastoskie, Christian M (committee member), Violi, Angela (committee member), Wooldridge, Margaret S (committee member).

Subjects/Keywords: advanced combustion; soot reactivity; PCCI combustion; post injection; soot nanostructure; renewable diesel; Mechanical Engineering; Engineering

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Sun, C. (2017). Nanostructure and Reactivity of Soot Produced from Partially Premixed Charge Compression Ignition (PCCI) Combustion and Post Injection. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/140920

Chicago Manual of Style (16^th Edition):

Sun, Chenxi. “Nanostructure and Reactivity of Soot Produced from Partially Premixed Charge Compression Ignition (PCCI) Combustion and Post Injection.” 2017. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/140920.

MLA Handbook (7^th Edition):

Sun, Chenxi. “Nanostructure and Reactivity of Soot Produced from Partially Premixed Charge Compression Ignition (PCCI) Combustion and Post Injection.” 2017. Web. 13 Apr 2021.

Vancouver:

Sun C. Nanostructure and Reactivity of Soot Produced from Partially Premixed Charge Compression Ignition (PCCI) Combustion and Post Injection. [Internet] [Doctoral dissertation]. University of Michigan; 2017. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/140920.

Council of Science Editors:

Sun C. Nanostructure and Reactivity of Soot Produced from Partially Premixed Charge Compression Ignition (PCCI) Combustion and Post Injection. [Doctoral Dissertation]. University of Michigan; 2017. Available from: http://hdl.handle.net/2027.42/140920

University of Michigan

12. Alzuabi, Mohammad. Imaging of Temperature Variations in the Near-Wall Region of an Optical Reciprocating Engine using Laser-Induced Fluorescence.

Degree: PhD, Mechanical Engineering, 2020, University of Michigan

URL: http://hdl.handle.net/2027.42/162972

► Understanding engine heat transfer can enable the design of more efficient engines with advanced operational strategies that reduce net carbon emissions. However, accurate predictions of… (more)

▼ Understanding engine heat transfer can enable the design of more efficient engines with advanced operational strategies that reduce net carbon emissions. However, accurate predictions of in-cylinder heat transfer processes require a significant investigation into the transient thermal boundary layer effects within the near-wall region (NWR). This work investigates the development of thermal stratification at two measurement locations near the cylinder head surface of an optical reciprocating engine using laser-induced fluorescence (LIF). Temperature images are obtained from high-speed toluene LIF measurements using the one-color detection technique, and the calibration procedure is based on predicted in-cylinder temperature from an engine simulation software (GT-Power). Precision uncertainty is assessed within a 1 x 1 mm2 calibration region, and found to be within ±2 K. First measurements examine temperature variations within a 20 x 12 mm2 field-of-view that includes the cylinder head and the piston top surfaces under motored operating conditions, while a second set of measurements examine temperature variations within an 8 x 6 mm2 field-of-view at the cylinder head surface under motored and fired operating conditions and at two different engine speeds. The near-wall temperature measurements of this work provide unique insights into the spatial and temporal temperature variations in the NWR of an optical reciprocating engine, which were enabled by a rigorous experimental effort and attentive post-processing steps to quantitatively process the LIF images to yield temperature fields. These measurements add to continuous effort to extend the fundamental understanding of near wall engine heat transfer, and aid in achieving a more comprehensive characterization of the NWR by complementing previously-collected near wall velocity measurements and a parallel effort in Large Eddy Simulations (LES) that focus on wall heat transfer. Future work should address improvements to the experimental methodology to better resolve the region within 0.5 mm from the surface, and perform simultaneous velocity field and surface temperature imaging to fully quantify turbulent heat fluxes, which are critical to understand heat transfer under transient high pressure, high-temperature conditions. Advisors/Committee Members: Sick, Volker (committee member), Bernal, Luis P (committee member), Boehman, Andre L (committee member), Reuss, David L (committee member).

Subjects/Keywords: Thermal stratification; Near-wall region; LIF thermometry; Optical engine; Mechanical Engineering; Engineering

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APA (6^th Edition):

Alzuabi, M. (2020). Imaging of Temperature Variations in the Near-Wall Region of an Optical Reciprocating Engine using Laser-Induced Fluorescence. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/162972

Chicago Manual of Style (16^th Edition):

Alzuabi, Mohammad. “Imaging of Temperature Variations in the Near-Wall Region of an Optical Reciprocating Engine using Laser-Induced Fluorescence.” 2020. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/162972.

MLA Handbook (7^th Edition):

Alzuabi, Mohammad. “Imaging of Temperature Variations in the Near-Wall Region of an Optical Reciprocating Engine using Laser-Induced Fluorescence.” 2020. Web. 13 Apr 2021.

Vancouver:

Alzuabi M. Imaging of Temperature Variations in the Near-Wall Region of an Optical Reciprocating Engine using Laser-Induced Fluorescence. [Internet] [Doctoral dissertation]. University of Michigan; 2020. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/162972.

Council of Science Editors:

Alzuabi M. Imaging of Temperature Variations in the Near-Wall Region of an Optical Reciprocating Engine using Laser-Induced Fluorescence. [Doctoral Dissertation]. University of Michigan; 2020. Available from: http://hdl.handle.net/2027.42/162972

University of Michigan

13. Schiffmann, Philipp. Root Causes of Cycle-to-Cycle Combustion Variations in Spark Ignited Engines.

Degree: PhD, Mechanical Engineering, 2016, University of Michigan

URL: http://hdl.handle.net/2027.42/133396

► Stricter governmental emission regulations, climate change concerns, and consumer demands for high fuel efficiency push the development of advanced cleaner and more efficient combustion strategies.… (more)

▼ Stricter governmental emission regulations, climate change concerns, and consumer demands for high fuel efficiency push the development of advanced cleaner and more efficient combustion strategies. Many strategies that rely on spark ignition are limited in their peak efficiencies by excessive cycle-to-cycle combustion variations (CCV). In this study, various laser-based and passive optical techniques are used to measure flow fields, spark discharge and other factors that impact early flame growth from which CCV originate. Bulk flow motion, as one contributing factor to CCV, is characterized in an optical engine under motored and fired conditions. In the fired cases, the flow velocities are higher during the gas exchange period but lower at the time of ignition, due to higher charge viscosities, caused by higher gas temperatures. Ten different fuel-air mixtures are strategically chosen to isolate the effects of laminar flame speed, thermo-diffusive mixture properties and change of stoichiometrically deficient species on the mechanisms that are responsible for cycle-to-cycle variability. Single value decomposition methods are found to be inefficient in identifying flow structures that are related to combustion variability. Physical flow parameters such as velocity magnitude and shear strength around time of ignition are identified to affect combustion variability. The relative impact of these parameters on energy output and combustion phasing are quantified for all mixtures and show some weak dependence on Markstein number and laminar flame speed. In a more fundamental fan-stirred combustion vessel experiments, variability effects of flame-flow interactions on CCV are isolated and thermo-diffusive effects are shown to impact combustion variability. Unstable negative Markstein number mixtures tend to exhibit higher combustion variability when interacting with gradients in the flow field around the time of ignition. High shear strength at the point of ignition causes an increased flame wrinkling, increasing the surface area, leading to faster combustion. This is an important finding because the common Lewis number equals 1 assumption in CFD simulations might lead to an under-prediction of CCV in low turbulence cases for negative Markstein number mixtures. Advisors/Committee Members: Sick, Volker (committee member), Raman, Venkatramanan (committee member), Boehman, Andre L (committee member), Reuss, David L (committee member), Keum, Seunghwan (committee member), Pera, Cecile (committee member).

Subjects/Keywords: Internal combustion engines; Combustion; Optical diagnostics; Cycle-to-cycle variations; PIV; Markstein number; Mechanical Engineering; Engineering

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APA (6^th Edition):

Schiffmann, P. (2016). Root Causes of Cycle-to-Cycle Combustion Variations in Spark Ignited Engines. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/133396

Chicago Manual of Style (16^th Edition):

Schiffmann, Philipp. “Root Causes of Cycle-to-Cycle Combustion Variations in Spark Ignited Engines.” 2016. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/133396.

MLA Handbook (7^th Edition):

Schiffmann, Philipp. “Root Causes of Cycle-to-Cycle Combustion Variations in Spark Ignited Engines.” 2016. Web. 13 Apr 2021.

Vancouver:

Schiffmann P. Root Causes of Cycle-to-Cycle Combustion Variations in Spark Ignited Engines. [Internet] [Doctoral dissertation]. University of Michigan; 2016. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/133396.

Council of Science Editors:

Schiffmann P. Root Causes of Cycle-to-Cycle Combustion Variations in Spark Ignited Engines. [Doctoral Dissertation]. University of Michigan; 2016. Available from: http://hdl.handle.net/2027.42/133396

University of Michigan

14. Triantopoulos, Vasileios. Experimental and Computational Investigation of Spark Assisted Compression Ignition Combustion Under Boosted, Ultra EGR-Dilute Conditions.

Degree: PhD, Mechanical Engineering, 2018, University of Michigan

URL: http://hdl.handle.net/2027.42/147508

► Low temperature combustion (LTC) engines that employ high levels of dilution have received increased research interest due to the demonstrated thermal efficiency improvements compared to… (more)

▼ Low temperature combustion (LTC) engines that employ high levels of dilution have received increased research interest due to the demonstrated thermal efficiency improvements compared to the conventional Spark-Ignited (SI) engines. However, control of combustion phasing and heat release rate still remains a challenge, which limits the operating range as well as the transient operation of LTC engines. The work presented in this dissertation uses experimental and computational methods to investigate Spark Assisted Compression Ignition (SACI) combustion under boosted, stoichiometric conditions with high levels of exhaust gas recirculation in a negative valve overlap engine. Highly controlled experimental studies were performed to understand the impact of intake boosting and fuel-to-charge equivalence ratio (φ') on SACI burn rates, while maintaining constant combustion phasing near the optimal timing for work extraction. Previously unexplored conditions were targeted at intake pressures ranging from 80 kPa to 150 kPa and φ' ranging from 0.45 to 0.75, where LTC engines promise high thermodynamic efficiencies. The use of intake boosting for load expansion and dilution extension achieved up to 10% gross thermal efficiency improvement, respectively, mainly due to reduced relative heat transfer losses and better mixture thermodynamic properties. For a given spark advance, higher pressure and/or higher φ' mixtures necessitated lower unburned gas temperatures (TU) to match autoignition timing. While the overall effect of intake boost was minor on the initial flame burn rates, end-gas autoignition rates were found to approximately scale with intake pressure. Higher φ' mixtures exhibited faster initial flame burn rates but also led to a significant increase in end-gas autoignition rates. As a result, the high load limits shifted to lower φ' at higher intake pressures, creating a larger gap between the SI and SACI operating limits. Reducing the mass fraction unburned at the onset of autoignition by advancing the spark timing and lowering TU was, to some extent, effective at alleviating the excessive peak pressure rise rates. Under relatively high φ' conditions, cyclic heat release analysis results showed that the variability in autoignition timing is determined early in the cycle before any measurable pressure-based heat release. Combustion phasing retard was shown to be very effective at limiting the maximum pressure rise rates until the stability limit, primarily due to slower end-gas autoignition rates. CFD modeling results showed good trendwise agreement with the experimental results, once autoignition timing and mass fraction burned at the onset of autoignition were matched. The pre-ignition reactivity stratification of the mixture at higher intake pressures was shown to be narrower, due to both lower thermal and compositional stratification, which explained the increase in end-gas burn rates observed experimentally. The boost pressure effect on SACI end-gas burn rates using intake manifold heating was trendwise similar… Advisors/Committee Members: Boehman, Andre L (committee member), Gamba, Mirko (committee member), Assanis, Dionissios N (committee member), Bohac, Stani V (committee member), Borgnakke, Claus (committee member), Martz, Jason Brian (committee member).

Subjects/Keywords: engines; thermodynamics; energy; efficiency; automotive; power; Mechanical Engineering; Engineering

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APA (6^th Edition):

Triantopoulos, V. (2018). Experimental and Computational Investigation of Spark Assisted Compression Ignition Combustion Under Boosted, Ultra EGR-Dilute Conditions. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/147508

Chicago Manual of Style (16^th Edition):

Triantopoulos, Vasileios. “Experimental and Computational Investigation of Spark Assisted Compression Ignition Combustion Under Boosted, Ultra EGR-Dilute Conditions.” 2018. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/147508.

MLA Handbook (7^th Edition):

Triantopoulos, Vasileios. “Experimental and Computational Investigation of Spark Assisted Compression Ignition Combustion Under Boosted, Ultra EGR-Dilute Conditions.” 2018. Web. 13 Apr 2021.

Vancouver:

Triantopoulos V. Experimental and Computational Investigation of Spark Assisted Compression Ignition Combustion Under Boosted, Ultra EGR-Dilute Conditions. [Internet] [Doctoral dissertation]. University of Michigan; 2018. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/147508.

Council of Science Editors:

Triantopoulos V. Experimental and Computational Investigation of Spark Assisted Compression Ignition Combustion Under Boosted, Ultra EGR-Dilute Conditions. [Doctoral Dissertation]. University of Michigan; 2018. Available from: http://hdl.handle.net/2027.42/147508

University of Michigan

15. Chang, Yan. Fuel Reforming for High Efficiency and Dilution Limit Extension of Spark-ignited Engines.

Degree: PhD, Mechanical Engineering, 2018, University of Michigan

URL: http://hdl.handle.net/2027.42/144107

► Engine efficiency improvement can help combustion powertrains, which include conventional, hybrid, and plug-in hybrid systems, to meet the strict emissions standards and the increasing demand… (more)

▼ Engine efficiency improvement can help combustion powertrains, which include conventional, hybrid, and plug-in hybrid systems, to meet the strict emissions standards and the increasing demand from customers for performance, drivability, and affordability of vehicles. Cooled exhaust gas recirculation (EGR) can reduce fuel consumption and NOx emissions of gasoline engine systems while keeping the capability of using a conventional three-way catalyst for effective emissions reduction. However, too much EGR would lead to combustion instability and misfire. This thesis identified opportunities to improve efficiency in internal combustion engines by high EGR dilution SI combustion by using thermodynamics-based approaches. This goal has been achieved by using fuel reforming in a thermodynamically-favorable way. Exhaust heat was used to drive endothermic reforming reactions to increase the chemical fuel energy to attain thermochemical recuperation (TCR), a form of waste heat recovery, with robust integrated systems and the regular gasoline. Three strategies for fuel reforming, along with the unique designs of corresponding integrated engine systems, a committed in-cylinder reformer, a catalytic EGR-loop reforming system, and fuel reforming by fuel injection during Negative Valve Overlap (NVO), have been proposed and investigated with unique engine system setups and corresponding experimental and simulation research. The concept and the system to use one cylinder to serve as a committed fuel reformer without spark ignition is first demonstrated. The committed in-cylinder reformer engine system achieves 8% brake thermal efficiency improvement through EGR and cylinder deactivation effects, even though there is low fuel conversion. The novel catalytic EGR-loop reforming integrated engine system was designed and tested. The experiments and thermodynamic equilibrium calculations reveal that the suppression of H2 and CO caused by the enthalpy limitation could be countered by adding small amounts of O2 by running one-cylinder lean. As much as 15 volume % H2 at the catalyst outlet is produced when the fuel and air equivalence ratio is between 4 and 7 under quasi-steady-state conditions. It is also found that this catalytic EGR reforming strategy makes it possible to sustain stable combustion with a volumetric equivalent of 45%–55% EGR, compared to a baseline EGR dilution limit which is under 25%. This catalytic EGR-loop reforming strategy results in a decrease of more than 8% in fuel consumption with significant potentials for even higher brake thermal efficiency. This novel design also opens up a new control method to control the amount of fuel reforming and the fraction of the partial oxidation reaction and steam reforming reaction by adjusting the lambda value of the cylinder which is running lean. Through this design, the engine is serving as an active system, which can also be adapted to respond to the needs of the passive catalyst system so that even better more significant benefit can be achieved. The results demonstrate… Advisors/Committee Members: Boehman, Andre L (committee member), Bohac, Stani V (committee member), Schwank, Johannes W (committee member), Fisher, Galen B (committee member), Szybist, James (committee member), Wooldridge, Margaret S (committee member).

Subjects/Keywords: Fuel Reforming; Thermal Efficiency; Vehicles; Mechanical Engineering; Engineering; Science

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APA (6^th Edition):

Chang, Y. (2018). Fuel Reforming for High Efficiency and Dilution Limit Extension of Spark-ignited Engines. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/144107

Chicago Manual of Style (16^th Edition):

Chang, Yan. “Fuel Reforming for High Efficiency and Dilution Limit Extension of Spark-ignited Engines.” 2018. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/144107.

MLA Handbook (7^th Edition):

Chang, Yan. “Fuel Reforming for High Efficiency and Dilution Limit Extension of Spark-ignited Engines.” 2018. Web. 13 Apr 2021.

Vancouver:

Chang Y. Fuel Reforming for High Efficiency and Dilution Limit Extension of Spark-ignited Engines. [Internet] [Doctoral dissertation]. University of Michigan; 2018. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/144107.

Council of Science Editors:

Chang Y. Fuel Reforming for High Efficiency and Dilution Limit Extension of Spark-ignited Engines. [Doctoral Dissertation]. University of Michigan; 2018. Available from: http://hdl.handle.net/2027.42/144107

University of Michigan

16. Easter, Jordan. Influence of Fuel Introduction Parameters on the Reactivity and Oxidation Process of Soot from a Gasoline Direct Injection Engine.

Degree: PhD, Mechanical Engineering, 2018, University of Michigan

URL: http://hdl.handle.net/2027.42/143938

► Upcoming regulations, such as Euro 6c, decrease limits on allowable tailpipe particulate number emissions. These regulations may place some current gasoline engine technologies above the… (more)

▼ Upcoming regulations, such as Euro 6c, decrease limits on allowable tailpipe particulate number emissions. These regulations may place some current gasoline engine technologies above the legal limit, especially those vehicles using direct fuel injection. Therefore, gasoline particulate filters (GPF) may be necessary for future emissions compliance. The key functionality of the GPF is filtration efficiency and control of this function is dependent on the soot build-up within the filter. The more soot present, the higher the filtration efficiency. As soot will often oxidize during much of the engine operation due to high temperatures and available oxygen, an understanding of soot reactivity and the degree to which reactivity may vary is key for designing after-treatment architecture and explaining low filtration efficiency results in real world situations. In this work, soot was evaluated from four conditions incorporating changes in the fuel injection pressure and timing, and the influence these parameter variations had on soot reactivity was evaluated through well-controlled isothermal and ramped oxidation events. It was determined that soot reactivity and the temperature by which oxidation would commence were quite different for the four samples. Following this, soot parameters known to influence reactivity were investigated. It was determined that nanostructure, volatile organic fraction and surface functional groups were similar between all four samples and though surface area was different, it did not correlate with reactivity. It was determined through estimations of the ash content that soot reactivity was likely influenced by the ash too soot ratio of the particulate matter. Ash is a known catalyst, found to enhance soot oxidation rates. The presence of ash and the interaction of soot and ash were investigated using a scanning transmission electron microscope coupled with energy dispersive x-ray spectroscopy (STEM+EDS). To carry further the investigation, soot samples from the most and least reactive condition underwent partial oxidation and the partially oxidized soots were analyzed to obtain information regarding the oxidation process. During oxidation, the soot particles appeared more amorphous and began to meld into each other, forming larger non-spherical particles. It was determined that beyond a sufficient ash-soot ratio, a ratio likely below 1% and easily reached for a modern gasoline direct injection engine, the soot oxidation process is marked by three distinct phases relating to interactions of ash and soot particles. In the first phase, the oxidation rate is enhanced by the presence of close soot to ash contact. Soot in close contact with the ash will oxidize first, leaving a loose contact between the ash and soot. This loose contact causes the observed distinction in the second stage. In the second stage, despite increases in the ash to soot ratio due to the loss of soot, the oxidation rate decreases due to the loose ash to soot contact. As oxidation proceeds, soot particles begin to meld… Advisors/Committee Members: Boehman, Andre L (committee member), Bohac, Stani V (committee member), Violi, Angela (committee member), Clack, Herek (committee member), Daley, James (committee member), Hoard, John W (committee member).

Subjects/Keywords: Reactivity of Gasoline Soot from Differing Fuel Introduction Parameters; Mechanical Engineering; Engineering

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APA (6^th Edition):

Easter, J. (2018). Influence of Fuel Introduction Parameters on the Reactivity and Oxidation Process of Soot from a Gasoline Direct Injection Engine. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/143938

Chicago Manual of Style (16^th Edition):

Easter, Jordan. “Influence of Fuel Introduction Parameters on the Reactivity and Oxidation Process of Soot from a Gasoline Direct Injection Engine.” 2018. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/143938.

MLA Handbook (7^th Edition):

Easter, Jordan. “Influence of Fuel Introduction Parameters on the Reactivity and Oxidation Process of Soot from a Gasoline Direct Injection Engine.” 2018. Web. 13 Apr 2021.

Vancouver:

Easter J. Influence of Fuel Introduction Parameters on the Reactivity and Oxidation Process of Soot from a Gasoline Direct Injection Engine. [Internet] [Doctoral dissertation]. University of Michigan; 2018. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/143938.

Council of Science Editors:

Easter J. Influence of Fuel Introduction Parameters on the Reactivity and Oxidation Process of Soot from a Gasoline Direct Injection Engine. [Doctoral Dissertation]. University of Michigan; 2018. Available from: http://hdl.handle.net/2027.42/143938

University of Michigan

17. Shingne, Prasad Sunand. Thermodynamic Modeling of HCCI Combustion with Recompression and Direct Injection.

Degree: PhD, Mechanical Engineering, 2015, University of Michigan

URL: http://hdl.handle.net/2027.42/113499

► Homogeneous Charge Compression Ignition (HCCI) engines have the potential to reduce pollutant emissions while achieving diesel-like thermal efficiencies. The absence of direct control over the… (more)

▼ Homogeneous Charge Compression Ignition (HCCI) engines have the potential to reduce pollutant emissions while achieving diesel-like thermal efficiencies. The absence of direct control over the start and rate of auto-ignition and a narrow load range makes implementation of HCCI engines into production vehicles a challenging affair. Effective HCCI combustion control can be achieved by manipulating the amount of residual gases trapped from the previous cycle by means of variable valve actuation. In turn, the temperature at intake valve closing and hence auto-ignition phasing can be controlled. Intake charge boosting can be used to increase HCCI fueling rates and loads, while other technologies such as direct injection provide means for achieving cycle to cycle phasing control. Thermodynamic zero-dimensional (0D) models are a computationally inexpensive tool for defining systems and strategies suitable for the implementation of new HCCI engine technologies. These models need to account for the thermal and compositional stratification in HCCI that control combustion rates. However these models are confined to a narrow range of engine operation given that the fundamental factors governing the combustion process are currently not well understood. CFD has therefore been used to understand the effect of operating conditions and input variables on pre-ignition charge stratification and combustion, allowing the development and use of a more accurate ignition model, which is proposed and validated here. A new empirical burn profile model is fit with mass fraction burned profiles from a large HCCI engine data set. The combined ignition model and burn correlation are then exercised and are shown capable of capturing the trends of a diverse range of transient HCCI experiments. However, the small cycle to cycle variations in combustion phasing are not captured by the model, possibly due to recompression heat release effects associated with variable valve actuation. Multi-cycle CFD simulations are therefore performed to gain physical insight into recompression heat release phenomena and the effect of these phenomena on the next cycle. Based on the understanding derived from this CFD work, a simple model of recompression heat release has been implemented in the 0D HCCI modeling framework. Advisors/Committee Members: Martz, Jason Brian (committee member), Assanis, Dionissios N. (committee member), Borgnakke, Claus (committee member), Driscoll, James F. (committee member), Boehman, Andre L. (committee member), Bohac, Stani V. (committee member).

Subjects/Keywords: HCCI; Combustion; Thermodynamics; 0D Modeling; Stratification; NVO heat release; Mechanical Engineering; Engineering

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APA (6^th Edition):

Shingne, P. S. (2015). Thermodynamic Modeling of HCCI Combustion with Recompression and Direct Injection. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/113499

Chicago Manual of Style (16^th Edition):

Shingne, Prasad Sunand. “Thermodynamic Modeling of HCCI Combustion with Recompression and Direct Injection.” 2015. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/113499.

MLA Handbook (7^th Edition):

Shingne, Prasad Sunand. “Thermodynamic Modeling of HCCI Combustion with Recompression and Direct Injection.” 2015. Web. 13 Apr 2021.

Vancouver:

Shingne PS. Thermodynamic Modeling of HCCI Combustion with Recompression and Direct Injection. [Internet] [Doctoral dissertation]. University of Michigan; 2015. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/113499.

Council of Science Editors:

Shingne PS. Thermodynamic Modeling of HCCI Combustion with Recompression and Direct Injection. [Doctoral Dissertation]. University of Michigan; 2015. Available from: http://hdl.handle.net/2027.42/113499

University of Michigan

18. Martin, Jonathan. Exploring the Combustion Modes of A Dual-Fuel Compression Ignition Engine.

Degree: PhD, Mechanical Engineering, 2019, University of Michigan

URL: http://hdl.handle.net/2027.42/153383

► Compression-ignition (CI) engines, also known as “diesel” engines, can produce higher thermal efficiency (TE) than spark-ignition (SI) engines, which allows them to emit less carbon… (more)

▼ Compression-ignition (CI) engines, also known as “diesel” engines, can produce higher thermal efficiency (TE) than spark-ignition (SI) engines, which allows them to emit less carbon dioxide (CO2) per unit of energy generated. Unfortunately, in practice the TE of CI engines is limited by the need to maintain sufficiently low emissions of nitrogen oxides (NOx) and soot. This problem can be mitigated by operating CI engines in dual-fuel modes with port fuel injection (PFI) of gasoline supplementing the direct injection (DI) of diesel fuel. Several strategies for doing this have been introduced in recent years, but these operating modes are usually studied individually at discrete conditions. This thesis introduces a classification system for dual-fuel CI modes that links together several previously studied modes across a continuous two-dimensional diagram. The combustion modes covered by this system include the standard modes of conventional diesel combustion (CDC) and conventional dual-fuel (CDF); the well-explored advanced combustion modes of HCCI, RCCI, PCCI, and PPCI; and a relatively unexplored combustion mode that is herein titled “Piston-split Dual-Fuel Combustion” or PDFC. The results show that dual-fuel CI engines can simultaneously increase TE and lower NOx and/or soot emissions at high loads through the use of Partial HCCI (PHCCI), despite an increase in emissions of carbon monoxide (CO) and unburnt hydrocarbons (UHC). At low loads, PHCCI is not possible, but either PDFC or RCCI can be used to further improve NOx and/or soot emissions, albeit at slightly lower TE and still higher emissions of CO and UHC. This multi-mode strategy of PHCCI at high loads and PDFC or RCCI at low loads is particularly useful when low engine-out NOx emissions are required. Advisors/Committee Members: Boehman, Andre L (committee member), Lastoskie, Christian M (committee member), Lavoie, George A (committee member), Middleton, Robert John (committee member), Wooldridge, Margaret S (committee member).

Subjects/Keywords: compression-ignition engines; dual-fuel combustion; advanced combustion modes; RCCI; HCCI; thermal efficiency; Mechanical Engineering; Engineering

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APA (6^th Edition):

Martin, J. (2019). Exploring the Combustion Modes of A Dual-Fuel Compression Ignition Engine. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/153383

Chicago Manual of Style (16^th Edition):

Martin, Jonathan. “Exploring the Combustion Modes of A Dual-Fuel Compression Ignition Engine.” 2019. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/153383.

MLA Handbook (7^th Edition):

Martin, Jonathan. “Exploring the Combustion Modes of A Dual-Fuel Compression Ignition Engine.” 2019. Web. 13 Apr 2021.

Vancouver:

Martin J. Exploring the Combustion Modes of A Dual-Fuel Compression Ignition Engine. [Internet] [Doctoral dissertation]. University of Michigan; 2019. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/153383.

Council of Science Editors:

Martin J. Exploring the Combustion Modes of A Dual-Fuel Compression Ignition Engine. [Doctoral Dissertation]. University of Michigan; 2019. Available from: http://hdl.handle.net/2027.42/153383

19. Singh, Ripudaman. Enabling Ethanol Use as a Renewable Transportation Fuel: A Micro- and Macro-scale Perspective.

Degree: PhD, Mechanical Engineering, 2019, University of Michigan

URL: http://hdl.handle.net/2027.42/149831

► The transportation sector remains the most challenging area to reduce greenhouse gas emissions from the combustion of fossil fuels. A successful transition away from fossil… (more)

▼ The transportation sector remains the most challenging area to reduce greenhouse gas emissions from the combustion of fossil fuels. A successful transition away from fossil fuels is possible through the use of ethanol as an alternative fuel. Ethanol has considerable promise to reduce the carbon intensity of passenger vehicles, but a better understanding of the promise and limitations of ethanol as a renewable energy carrier is required, particularly using non-food feedstocks. Blending ethanol with gasoline has been demonstrated at a significant scale in the United States and Brazil. Currently, ethanol is blended with gasoline in the U.S. as an octane booster to a maximum blend level (E10 – 10% by volume); which is indistinguishable from gasoline to the engine application and the fueling infrastructure. However, optimum blend levels have not been determined from an engine application perspective. Also, current production of ethanol from primary food crops presents challenges like competition with food sources; thus, alternative feedstocks for ethanol production are required. This dissertation takes a novel approach which presents micro and macro-scale perspectives to enable ethanol as a transportation fuel. First at the micro or device scale, physical experiments were used to determine the optimum blend level of ethanol and gasoline for production spark ignition engines. Engine operating strategies which provide the most benefit, in terms of improving efficiency and lowering emissions, with the use of these blends were identified. Mid-level blends (30%) of ethanol by volume with gasoline show the most benefit in terms of several engine performance metrics. An improvement of 2% in thermodynamic efficiency on an absolute basis, and more than 90% reduction in particulate emissions was observed by combining use of such a blend with a triple-injection per cycle fueling strategy. Second at the macro scale of the transportation fuel production and distribution level, analytical methods were applied to determine the feasibility of producing cellulosic ethanol based on high-fidelity geographically-resolved data on agricultural waste for the regional districts of Ghana. Biorefinery locations and fuel blending infrastructure recommendations are made, by minimizing transportation costs involved in the biomass residue feedstock collection and distribution of the ethanol produced by the biorefinery. Previous studies have shown significant potential of biofuel production in Ghana, but there were no previous studies that focused on development of geographic infrastructure for 2nd generation transportation biofuels (i.e. based on non-food feedstocks). This study was the first attempt in this direction. Both the process used and the outcomes of this study provide valuable input for the development of sustainable biofuels infrastructure in Ghana. This work demonstrates considerable benefit of ethanol blending for modern engine architecture, with identification of strategies which leverage the thermo-physical fuel properties of… Advisors/Committee Members: Wooldridge, Margaret S (committee member), Gamba, Mirko (committee member), Boehman, Andre L (committee member), Keoleian, Gregory A (committee member), Mansfield, Andrew Benjamin (committee member).

Subjects/Keywords: spark ignition engine; gasoline direct injection; cellulosic ethanol; thermodynamic efficiency; particulate emissions; Ghana; Mechanical Engineering; Engineering

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APA (6^th Edition):

Singh, R. (2019). Enabling Ethanol Use as a Renewable Transportation Fuel: A Micro- and Macro-scale Perspective. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/149831

Chicago Manual of Style (16^th Edition):

Singh, Ripudaman. “Enabling Ethanol Use as a Renewable Transportation Fuel: A Micro- and Macro-scale Perspective.” 2019. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/149831.

MLA Handbook (7^th Edition):

Singh, Ripudaman. “Enabling Ethanol Use as a Renewable Transportation Fuel: A Micro- and Macro-scale Perspective.” 2019. Web. 13 Apr 2021.

Vancouver:

Singh R. Enabling Ethanol Use as a Renewable Transportation Fuel: A Micro- and Macro-scale Perspective. [Internet] [Doctoral dissertation]. University of Michigan; 2019. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/149831.

Council of Science Editors:

Singh R. Enabling Ethanol Use as a Renewable Transportation Fuel: A Micro- and Macro-scale Perspective. [Doctoral Dissertation]. University of Michigan; 2019. Available from: http://hdl.handle.net/2027.42/149831

20. Choi, Jeongyong. Recycled Water Injection in a Turbocharged Gasoline Engine and Detailed Effects of Water on Auto-Ignition.

Degree: PhD, Mechanical Engineering, 2019, University of Michigan

URL: http://hdl.handle.net/2027.42/149814

► In recent years, many engine manufacturers have turned to downsizing and boosting of gasoline engines in order to meet the ever more stringent fuel economy… (more)

▼ In recent years, many engine manufacturers have turned to downsizing and boosting of gasoline engines in order to meet the ever more stringent fuel economy and emissions regulations. With an increase in the number of turbocharged gasoline engines, solutions are required to manage knock under a range of operating conditions. The engine is required to operate with spark retard and/or boost reduction to provide knock reduction leading to reduced fuel economy. The charge air cooler has been introduced to mitigate knock and yield a denser intake charge. However, under certain conditions, water condenses onto the charge air cooler inner surfaces, and this water can be introduced into the combustion chamber. Therefore, water ingestion may cause abnormal combustion. In addition, many researchers have advocated water injection as an approach to replace or supplement existing knock mitigation techniques. To maximize the efficiency of the water injection system for a given amount of water, a deeper understanding of the ability to capture and utilize water is required. The first part of this dissertation pursues an understanding of the condensates generated inside of the charge air cooler is discussed. To understand the ingestion of condensates into the cylinders, the hard acceleration is applied with the condensates and quantitatively correlated the amount of condensation and number of abnormal combustion behavior such as misfire and slowburn in different engine conditions. The next study is designing the condensation separator to prevent the abnormal combustion behavior due to the condensates ingestion. An approach to designing a unit to separate condensation in the flow from the charge air cooler while maintaining a low pressure drop is described. The effect of water on auto-ignition is described using modified CFR engine. Three test fuels gasoline, PRF, and TRF which have similar RON blends are used for this test at various intake pressure and amount of water conditions. The first test is done with constant intake air temperature and φ to exclude the effects of intake air cooling. For the second part of this research, the comparison of the effect of the intake air cooling and the effect of the intake air property change is made. The numerical calculations of the chemical effect of water addition with high octane number fuels and oxygenated fuels such as iso-Octane, toluene, n-Butanol, and Ethanol are presented. Using chemical reaction simulation, CHEMKIN, the simulations have been conducted on the change of hydrocarbon and oxygenated hydrocarbon oxidations process with water addition by examining ignition delay, sensitivity analysis and chemical reaction pathway analysis. At the beginning of the study, change of the ignition delay due to water addition is quantified. Then, the sensitivity analysis and the reaction pathway analysis are carried out to verify more detail of chemical effect of water on combustion process. Through the studies presented in this thesis, some of potential contributions to high efficiency… Advisors/Committee Members: Boehman, Andre L (committee member), Hoard, John W (committee member), Raman, Venkatramanan (committee member), Violi, Angela (committee member).

Subjects/Keywords: Charge air cooler condensate; Water injection; Mechanical Engineering; Engineering

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APA (6^th Edition):

Choi, J. (2019). Recycled Water Injection in a Turbocharged Gasoline Engine and Detailed Effects of Water on Auto-Ignition. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/149814

Chicago Manual of Style (16^th Edition):

Choi, Jeongyong. “Recycled Water Injection in a Turbocharged Gasoline Engine and Detailed Effects of Water on Auto-Ignition.” 2019. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/149814.

MLA Handbook (7^th Edition):

Choi, Jeongyong. “Recycled Water Injection in a Turbocharged Gasoline Engine and Detailed Effects of Water on Auto-Ignition.” 2019. Web. 13 Apr 2021.

Vancouver:

Choi J. Recycled Water Injection in a Turbocharged Gasoline Engine and Detailed Effects of Water on Auto-Ignition. [Internet] [Doctoral dissertation]. University of Michigan; 2019. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/149814.

Council of Science Editors:

Choi J. Recycled Water Injection in a Turbocharged Gasoline Engine and Detailed Effects of Water on Auto-Ignition. [Doctoral Dissertation]. University of Michigan; 2019. Available from: http://hdl.handle.net/2027.42/149814

21. Mazacioglu, Ahmet. Infrared Borescopic Characterization of Ignition and Combustion Variability in Heavy-Duty Natural-Gas Engines.

Degree: PhD, Mechanical Engineering, 2019, University of Michigan

URL: http://hdl.handle.net/2027.42/149912

► Natural gas (NG) is attractive for heavy-duty (HD) engines for reasons of cost stability, emissions, and fuel security. NG requires forced ignition, but conventional gasoline-engine… (more)

▼ Natural gas (NG) is attractive for heavy-duty (HD) engines for reasons of cost stability, emissions, and fuel security. NG requires forced ignition, but conventional gasoline-engine ignition systems are not optimized for NG and are challenged to ignite mixtures that are lean or diluted with exhaust-gas recirculation (EGR). NG ignition is particularly difficult in large-bore engines, where it is more challenging to complete combustion in the time available. High-speed infrared (IR) in-cylinder imaging and image-derived quantitative metrics were used to compare four ignition systems in terms of the early flame-kernel development and cycle-to-cycle variability (CCV) in a heavy-duty, natural-gas-fueled engine that had been modified to enable exhaust-gas recirculation and to provide optical access via borescopes. Imaging in the near IR and short-wavelength IR yielded strong signals from the water emission lines, which acted as a proxy for flame front and burned-gas regions while obviating image intensification (which can reduce spatial resolution). Four ignition technologies were studied: a conventional system delivering 65 mJ of energy to each spark, a high-energy conventional system delivering 140 mJ, a Bosch Controlled Electronic Ignition (CEI) system, which uses electronics to extend the duration and the energy of the ignition event, and a high-frequency corona system (BorgWarner EcoFlash). The corona system produced five separate elongated, irregularly shaped, nonequilibrium-plasma streamers, leading to immediate formation of five spatially distinct wrinkled flame kernels around each streamer. The high-speed infrared borescopic imaging diagnostic developed here is shown to be an excellent method to accurately identify small flame kernels without the need of image intensifiers, comparable to intensified OH* imaging but with reduced experimental complexity. The results acquired from the production engine under varying air/fuel equivalence ratios and EGR rates uniquely demonstrate that stretched and wrinkled early flame kernels have a great advantage over spherical flames to complete combustion faster, and unlike conventional igniters, corona ignition system produces such flame kernels repeatably without heavy reliance on the flow and compositional conditions of the mixture. Advisors/Committee Members: Gross, Michael Charles (committee member), Sick, Volker (committee member), Kushner, Mark (committee member), Boehman, Andre L (committee member).

Subjects/Keywords: Ignition; Natural Gas; Infrared Imaging; Corona Ignition; Borescopic / Endoscopic Imaging; Cycle-to-Cycle Variations; Mechanical Engineering; Engineering

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APA (6^th Edition):

Mazacioglu, A. (2019). Infrared Borescopic Characterization of Ignition and Combustion Variability in Heavy-Duty Natural-Gas Engines. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/149912

Chicago Manual of Style (16^th Edition):

Mazacioglu, Ahmet. “Infrared Borescopic Characterization of Ignition and Combustion Variability in Heavy-Duty Natural-Gas Engines.” 2019. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/149912.

MLA Handbook (7^th Edition):

Mazacioglu, Ahmet. “Infrared Borescopic Characterization of Ignition and Combustion Variability in Heavy-Duty Natural-Gas Engines.” 2019. Web. 13 Apr 2021.

Vancouver:

Mazacioglu A. Infrared Borescopic Characterization of Ignition and Combustion Variability in Heavy-Duty Natural-Gas Engines. [Internet] [Doctoral dissertation]. University of Michigan; 2019. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/149912.

Council of Science Editors:

Mazacioglu A. Infrared Borescopic Characterization of Ignition and Combustion Variability in Heavy-Duty Natural-Gas Engines. [Doctoral Dissertation]. University of Michigan; 2019. Available from: http://hdl.handle.net/2027.42/149912

22. Gorzelic, Patrick H. Modeling and Model-Based Control Of Multi-Mode Combustion Engines for Closed-Loop SI/HCCI Mode Transitions with Cam Switching Strategies.

Degree: PhD, Mechanical Engineering, 2015, University of Michigan

URL: http://hdl.handle.net/2027.42/113351

► Homogeneous charge compression ignition (HCCI) combustion has been investigated by many researchers as a way to improve gasoline engine fuel economy through highly dilute unthrottled… (more)

▼ Homogeneous charge compression ignition (HCCI) combustion has been investigated by many researchers as a way to improve gasoline engine fuel economy through highly dilute unthrottled operation while maintaining acceptable tailpipe emissions. A major concern for successful implementation of HCCI is that it's feasible operating region is limited to a subset of the full engine regime, which necessitates mode transitions between HCCI and traditional spark ignition (SI) combustion when the HCCI region is entered/exited. The goal of this dissertation is to develop a methodology for control-oriented modeling and model-based feedback control during such SI/HCCI mode transitions. The model-based feedback control approach is sought as an alternative to those in the SI/HCCI transition literature, which predominantly employ open-loop experimentally derived actuator sequences for generation of control input trajectories. A model-based feedback approach has advantages both for calibration simplicity and controller generality, in that open-loop sequences do not have to be tuned, and that use of nonlinear model-based calculations and online measurements allows the controller to inherently generalize across multiple operating points and compensate for case-by-case disturbances. In the dissertation, a low-order mean value modeling approach for multi-mode SI/HCCI combustion that is tractable for control design is described, and controllers for both the SI to HCCI (SI-HCCI) and HCCI to SI (HCCI-SI) transition are developed based on the modeling approach. The model is shown to fit a wide range of steady-state actuator sweep data containing conditions pertinent to SI/HCCI mode transitions, and is extended to capture transient SI-HCCI transition data through using an augmented residual gas temperature parameter. The mode transition controllers are experimentally shown to carry out SI-HCCI and HCCI-SI transitions in several operating conditions with minimal tuning, though the validation in the SI-HCCI direction is more extensive. The model-based control architecture is also equipped with an online parameter updating routine, to attenuate error in model-based calculations and improve robustness to engine aging and cylinder to cylinder variability. Experimental examples at multiple operating conditions illustrate the ability of the parameter update routine to improve controller performance by using transient data to tune the model parameters for enhanced accuracy during SI-HCCI mode transitions. Advisors/Committee Members: Stefanopoulou, Anna G. (committee member), Kolmanovsky, Ilya Vladimir (committee member), Hellstrom, Erik (committee member), Boehman, Andre L. (committee member).

Subjects/Keywords: Combustion Mode Transition Control; SI-HCCI Transition Control; HCCI-SI Transition Control; Model-Based Feedback Control; Mechanical Engineering; Engineering

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APA (6^th Edition):

Gorzelic, P. H. (2015). Modeling and Model-Based Control Of Multi-Mode Combustion Engines for Closed-Loop SI/HCCI Mode Transitions with Cam Switching Strategies. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/113351

Chicago Manual of Style (16^th Edition):

Gorzelic, Patrick H. “Modeling and Model-Based Control Of Multi-Mode Combustion Engines for Closed-Loop SI/HCCI Mode Transitions with Cam Switching Strategies.” 2015. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/113351.

MLA Handbook (7^th Edition):

Gorzelic, Patrick H. “Modeling and Model-Based Control Of Multi-Mode Combustion Engines for Closed-Loop SI/HCCI Mode Transitions with Cam Switching Strategies.” 2015. Web. 13 Apr 2021.

Vancouver:

Gorzelic PH. Modeling and Model-Based Control Of Multi-Mode Combustion Engines for Closed-Loop SI/HCCI Mode Transitions with Cam Switching Strategies. [Internet] [Doctoral dissertation]. University of Michigan; 2015. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/113351.

Council of Science Editors:

Gorzelic PH. Modeling and Model-Based Control Of Multi-Mode Combustion Engines for Closed-Loop SI/HCCI Mode Transitions with Cam Switching Strategies. [Doctoral Dissertation]. University of Michigan; 2015. Available from: http://hdl.handle.net/2027.42/113351

23. Barraza Botet, Cesar. Combustion Chemistry and Physics of Ethanol Blends to Inform Biofuel Policy.

Degree: PhD, Mechanical Engineering, 2018, University of Michigan

URL: http://hdl.handle.net/2027.42/143932

► This dissertation provides new fundamental and quantitative understanding of the combustion chemistry and physics of ethanol and ethanol blends. The results provide a means to… (more)

▼ This dissertation provides new fundamental and quantitative understanding of the combustion chemistry and physics of ethanol and ethanol blends. The results provide a means to inform strategic energy policy-making in the transportation sector. Scientifically informed vehicle regulation can drive the development of technologies that optimize fuel performance and minimize pollutant emissions when using ethanol to displace gasoline. In this work, two experimental facilities were used to study the global reactivity and detailed ignition chemistry of ethanol, iso-octane and ethanol/iso-octane blends at conditions relevant to advanced engine strategies. Rapid compression facility (RCF) studies were used to quantify global reactivity in terms of ignition delay times and to provide new data on the reaction pathways of pollutant species like aldehydes and soot precursors. The RCF ignition study of ethanol/iso-octane blends demonstrated their reactivity tends to increase with the carbon content in the blend within the limits defined by pure ethanol and pure iso-octane across the range of temperatures studied. Furthermore, the reaction pathways of each fuel develop independently with no significant fuel-to-fuel interactions, but with a shared radical pool. At the same conditions of the RCF studies, ignition quality tester (IQT) studies of ethanol/iso-octane blends considered the effects of spray injection physics, stratification and mixing effects on the fuel blend reactivity. The results showed that although thermal-fluid effects reduced the overall reactivity for all the blends studied, the chemistry effects dominate the temperature dependence for all blends and conditions studied. The results of these studies represent vital data for developing, validating and verifying the combustion chemistry of detailed and reduced chemical kinetic models for ethanol blends, which are used to predict global reactivity and pollutant formation in fundamental and applied combustion systems. The quantitative understanding of the chemistry behind the knock resistance attributes and pollutant formation pathways of ethanol and ethanol blends can allow regulatory agencies to set more ambitious and simultaneously more realistic efficiency and emission standards for integrating ethanol into the transportation infrastructure. Advisors/Committee Members: Wooldridge, Margaret S (committee member), Fogler, Hugh Scott (committee member), Boehman, Andre L (committee member), Raman, Venkatramanan (committee member).

Subjects/Keywords: Ethanol blends, ignition time scales, speciation, reaction pathways, fuel-to-fuel interactions, physico-chemical interactions, biofuel policy; Aerospace Engineering; Chemical Engineering; Engineering (General); Mechanical Engineering; Transportation; Government Information; Engineering; Government Information and Law

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APA (6^th Edition):

Barraza Botet, C. (2018). Combustion Chemistry and Physics of Ethanol Blends to Inform Biofuel Policy. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/143932

Chicago Manual of Style (16^th Edition):

Barraza Botet, Cesar. “Combustion Chemistry and Physics of Ethanol Blends to Inform Biofuel Policy.” 2018. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/143932.

MLA Handbook (7^th Edition):

Barraza Botet, Cesar. “Combustion Chemistry and Physics of Ethanol Blends to Inform Biofuel Policy.” 2018. Web. 13 Apr 2021.

Vancouver:

Barraza Botet C. Combustion Chemistry and Physics of Ethanol Blends to Inform Biofuel Policy. [Internet] [Doctoral dissertation]. University of Michigan; 2018. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/143932.

Council of Science Editors:

Barraza Botet C. Combustion Chemistry and Physics of Ethanol Blends to Inform Biofuel Policy. [Doctoral Dissertation]. University of Michigan; 2018. Available from: http://hdl.handle.net/2027.42/143932

24. Nuesch, Sandro Patrick. Analysis and Control of Multimode Combustion Switching Sequence.

Degree: PhD, Mechanical Engineering, 2015, University of Michigan

URL: http://hdl.handle.net/2027.42/116660

► Highly dilute, low temperature combustion technologies, such as homogeneous charge compression ignition (HCCI), show significant improvements in internal combustion engine fuel efficiency and engine-out NOx… (more)

▼ Highly dilute, low temperature combustion technologies, such as homogeneous charge compression ignition (HCCI), show significant improvements in internal combustion engine fuel efficiency and engine-out NOx emissions. These improvements, however, occur at limited operating range and conventional spark ignition (SI) combustion is still required to fulfill the driver's high torque demands. In consequence, such multimode engines involve discrete switches between the two distinct combustion modes. Such switches unfortunately require a finite amount of time, during which they exhibit penalties in efficiency. Along with its challenges, the design of such a novel system offers new degrees of freedom in terms of engine and aftertreatment specifications. Prior assessments of this technology were based on optimistic assumptions and neglected switching dynamics. Furthermore, emissions and driveability were not fully addressed. To this end, a comprehensive simulation framework, which accounts for above-mentioned penalties and incorporates interactions between multimode engine, driveline, and three-way catalyst (TWC), has been developed. Experimental data was used to parameterize a novel mode switch model, formulated as finite-state machine. This model was combined with supervisory controller designs, which made the switching decision. The associated drive cycle results were analyzed and it was seen that mode switches have significant influence on overall fuel economy, and the issue of drivability needs to be addressed within the supervisory strategy. After expanding the analysis to address emissions assuming a TWC, it was shown that, in practice, HCCI operation requires the depletion of the TWC's oxygen storage capacity (OSC). For large OSCs the resulting lean-rich cycling nullifies HCCI's original efficiency benefits. In addition, future emissions standards are still unlikely to be fulfilled, deeming a system consisting of such a multimode engine and TWC with generous OSC unfavorable. In view of these difficulties, the modeling framework was extended to a mild hybrid electric vehicle (HEV) allowing a prolonged operation in HCCI mode with associated fuel economy benefits during city driving. Further analysis on how to reduce NOx while maintaining fuel economy resulted in a counterintuitive suggestion. It was deemed beneficial to constrain the HCCI operation to a small region, exhibiting lowest NOx, while reducing instead of increasing the OSC. Advisors/Committee Members: Stefanopoulou, Anna G (committee member), Kolmanovsky, Ilya Vladimir (committee member), Boehman, Andre L (committee member), Martz, Jason Brian (committee member).

Subjects/Keywords: Internal combustion engine; Supervisory control of a multimode combustion engine; Homogeneous charge compression ignition (HCCI); Drive cycle analysis for fuel economy and emissions; Mechanical Engineering; Engineering

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APA (6^th Edition):

Nuesch, S. P. (2015). Analysis and Control of Multimode Combustion Switching Sequence. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/116660

Chicago Manual of Style (16^th Edition):

Nuesch, Sandro Patrick. “Analysis and Control of Multimode Combustion Switching Sequence.” 2015. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/116660.

MLA Handbook (7^th Edition):

Nuesch, Sandro Patrick. “Analysis and Control of Multimode Combustion Switching Sequence.” 2015. Web. 13 Apr 2021.

Vancouver:

Nuesch SP. Analysis and Control of Multimode Combustion Switching Sequence. [Internet] [Doctoral dissertation]. University of Michigan; 2015. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/116660.

Council of Science Editors:

Nuesch SP. Analysis and Control of Multimode Combustion Switching Sequence. [Doctoral Dissertation]. University of Michigan; 2015. Available from: http://hdl.handle.net/2027.42/116660

25. Kiwan, Rani. On the Estimation of Exhaust Gas Recirculation Flow and Waste Heat Recovery Tradeoffs Based on Differential Pressure Measurements.

Degree: PhD, Mechanical Engineering, 2019, University of Michigan

URL: http://hdl.handle.net/2027.42/151426

► Both exhaust gas recirculation (EGR) and waste heat recovery (WHR) are attractive technologies for more efficient spark ignition (SI) engines. The fuel economy benefit of… (more)

▼ Both exhaust gas recirculation (EGR) and waste heat recovery (WHR) are attractive technologies for more efficient spark ignition (SI) engines. The fuel economy benefit of cooled external EGR on SI engines is well established, and preliminary first law analysis of engine energy flows indicates the large potential for efficiency improvements with WHR. Nevertheless, both technologies face major challenges that need to be addressed to become viable solutions for more efficient SI engines. Cooled external EGR improves SI engine efficiency under wide range of conditions. However, inaccurate estimation of the EGR fraction in the intake manifold can be detrimental as it can lead to inaccurate air charge estimation, knock and misfire. Accurate EGR estimation based on a differential pressure (ΔP) measurement is very challenging at the low ΔP 's due to pressure pulsations and inertial effects. While some systems are capable of increasing ΔP across the EGR valve to improve EGR estimation, the higher ΔP is undesirable as it can increase pumping losses. EGR estimation accuracy at low ΔP can be improved by fast sampling of the ΔP signal and using the newly derived approximations of the unsteady compressible flow orifice equation. Both experimental data from a modified Ford 1.6 L EcoBoost engine with added LP and HP-EGR loops, and simulation predictions from its GT-Power models are used to evaluate the estimation methods. A sampling frequency of at least 1 kHz reduces the ΔP lower bound required to keep the LP and HP-EGR estimation error within a target 1% from 12.7 and 27.9 to 1.9 and 2.9 kPa respectively. The LP ΔP lower bound can be further reduced to 1.1 kPa with variable filtering, but the sampling frequency requirement is increased to 3 kHz to achieve the full benefit. The impact of gauge-line distortions and EGR valve area offset errors are also evaluated. An extension of a preexisting lumped parameter model is proposed to estimate the actual ΔP from the distorted measurement. Simulation results show that the proposed model can correct for the gauge-line errors under modeled pressure measurement noise. Valve area offset errors are shown to have substantial impact on the EGR estimation error especially for the HP-EGR case. A novel online calibration method for the HP-EGR valve area using preexisting engine sensors is developed and shown to have promise for implementation. The second part of this thesis studies the limitations and challenges of WHR through electric turbo-generation. Insights into the tradeoffs between exhaust energy recovery and increased pumping losses from the flow restriction of the electric turbo-generator (eTG) are provided and assessed using thermodynamic principles and with a detailed GT-Power engine model. The additional pumping losses are load independent and cannot be offset by the eTG power at low loads. Engine simulations are used to predict the influence of the increased back pressure on pumping work, in-cylinder residuals and combustion. The eTG is detrimental at the high loads as it requires… Advisors/Committee Members: Stefanopoulou, Anna G (committee member), Hofmann, Heath (committee member), Boehman, Andre L (committee member), Middleton, Robert John (committee member).

Subjects/Keywords: Estimation of Exhaust Gas Recirculation Flow based on Pressure Measurements; Waste Heat Recovery Tradeoffs; Mechanical Engineering; Engineering

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APA (6^th Edition):

Kiwan, R. (2019). On the Estimation of Exhaust Gas Recirculation Flow and Waste Heat Recovery Tradeoffs Based on Differential Pressure Measurements. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/151426

Chicago Manual of Style (16^th Edition):

Kiwan, Rani. “On the Estimation of Exhaust Gas Recirculation Flow and Waste Heat Recovery Tradeoffs Based on Differential Pressure Measurements.” 2019. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/151426.

MLA Handbook (7^th Edition):

Kiwan, Rani. “On the Estimation of Exhaust Gas Recirculation Flow and Waste Heat Recovery Tradeoffs Based on Differential Pressure Measurements.” 2019. Web. 13 Apr 2021.

Vancouver:

Kiwan R. On the Estimation of Exhaust Gas Recirculation Flow and Waste Heat Recovery Tradeoffs Based on Differential Pressure Measurements. [Internet] [Doctoral dissertation]. University of Michigan; 2019. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/151426.

Council of Science Editors:

Kiwan R. On the Estimation of Exhaust Gas Recirculation Flow and Waste Heat Recovery Tradeoffs Based on Differential Pressure Measurements. [Doctoral Dissertation]. University of Michigan; 2019. Available from: http://hdl.handle.net/2027.42/151426

26. Koh, Hyun Seung. Computational Discovery of Metal-Organic Frameworks for Carbon Capture and Natural Gas Storage.

Degree: PhD, Mechanical Engineering, 2014, University of Michigan

URL: http://hdl.handle.net/2027.42/110395

► Metal-organic frameworks (MOFs) have recently emerged as promising materials for the capture of carbon dioxide (CO2) and the storage of alternative fuels such as methane… (more)

▼ Metal-organic frameworks (MOFs) have recently emerged as promising materials for the capture of carbon dioxide (CO2) and the storage of alternative fuels such as methane (CH4). Amongst the many possible MOFs, metal-substituted compounds based on Ni-DOBDC and HKUST-1 have demonstrated the highest capacities for CO2 and CH4. Here we explore the possibility for additional performance tuning within these compounds by computationally screening several metal-substituted variants with respect to their CO2 adsorption enthalpies and CH4 capacities. These compounds are denoted M-DOBDC and M-HKUST-1, where M refers to the composition of the coordinatively unsaturated metal site (CUS), which is varied amongst 18 possible substitutions. Calculations are performed using a variety of techniques, ranging from dispersion-corrected Density Functional Theory to classical Monte Carlo, with the latter simulations employing customized interatomic potentials tuned by first-principles calculations. Regarding CO2 capture, we find that substitutions involving alkaline earth metals and early transition metals yield relatively strong affinities for CO2. Several compositions having adsorption enthalpies within the targeted thermodynamic window were identified. The electronic structure of the MOF/CO2 interaction was characterized and used to rationalize trends in CO2 affinity. In particular, the partial charge on the CUS is found to correlate with the adsorption enthalpy, suggesting that this property may be used as a simple descriptor for carbon captures efficiency. Regarding methane storage, adsorption isotherms were predicted using Grand Canonical Monte Carlo simulations across the M-DOBDC and M-HKUST-1 series, and for hundreds of other MOFs mined from the Cambridge Structure Database. A distinguishing feature of this work is the development of tuned interatomic potentials that properly capture the interaction between CH4 and CUS. The potential developed here reproduces the experimental isotherm for the benchmark Cu-HKUST-1 system very well; consequently, this approach was extended to predict CH4 uptake across the M-HKUST-1 series. Our calculations suggest that Ca-HKUST-1 and Fe-HKUST-1 should exceed the performance of Cu-HKUST-1, which currently holds the record for highest measured methane storage capacity. These compositions are suggested as promising targets for experimental testing. Screening metal-substituted variants of additional MOFs containing the same Cu-paddlewheel unit present in HKUST-1 is suggested as an extension of this work. Advisors/Committee Members: Siegel, Donald Jason (committee member), Matzger, Adam J. (committee member), Boehman, Andre L. (committee member), Lu, Wei (committee member).

Subjects/Keywords: Metal-Organic Frameworks; Density Functional Theory; Grand Canonical Monte Carlo; Gas Capture and Storage; Materials Discovery; Atomistic Modeling; Computer Science; Materials Science and Engineering; Mechanical Engineering; Engineering

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APA (6^th Edition):

Koh, H. S. (2014). Computational Discovery of Metal-Organic Frameworks for Carbon Capture and Natural Gas Storage. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/110395

Chicago Manual of Style (16^th Edition):

Koh, Hyun Seung. “Computational Discovery of Metal-Organic Frameworks for Carbon Capture and Natural Gas Storage.” 2014. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/110395.

MLA Handbook (7^th Edition):

Koh, Hyun Seung. “Computational Discovery of Metal-Organic Frameworks for Carbon Capture and Natural Gas Storage.” 2014. Web. 13 Apr 2021.

Vancouver:

Koh HS. Computational Discovery of Metal-Organic Frameworks for Carbon Capture and Natural Gas Storage. [Internet] [Doctoral dissertation]. University of Michigan; 2014. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/110395.

Council of Science Editors:

Koh HS. Computational Discovery of Metal-Organic Frameworks for Carbon Capture and Natural Gas Storage. [Doctoral Dissertation]. University of Michigan; 2014. Available from: http://hdl.handle.net/2027.42/110395

27. Kwak, Kyoung Hyun. Fuel Sensitive Combustion Model Based On Quasi-Dimensional Multi-Zone Approach For Direct Injection Compression Ignition Engines.

Degree: PhD, Mechanical Engineering, 2014, University of Michigan

URL: http://hdl.handle.net/2027.42/108990

► This study describes a development of fuel sensitive quasi-dimensional multi-zone model for a direct injection compression ignition (DICI) engine. The objective is to develop fuel… (more)

▼ This study describes a development of fuel sensitive quasi-dimensional multi-zone model for a direct injection compression ignition (DICI) engine. The objective is to develop fuel sensitive sub models of the DICI combustion process and integrate them into a thermodynamic engine cycle simulation. The proposed spray and evaporation models comprise the sub-models including fuel sensitive spray breakup, improved zone velocity estimations with transient fuel injection, spray penetration and tracking of evaporated fuel components. On these foundations, ignition delay models are formulated with two different descriptions based on the origin of the charge properties in a DICI engine. The global ignition delay model is based on the global combustion chamber charge properties while the local ignition delay model includes variations in properties of each spray zones. The Cetane number is used to describe a fuel effect for both models. Then, the premixed combustion model is reformulated to calculate a proper burn rate profile with respect to equivalence ratio and scale the profile with diluted air. While the developed models are validated and evaluated by comparing the predictions with experimental data, some of important conclusions have been made. In the spray formation model, the degree of viscosity and surface tension effect on the spray formation and air entrainment is much more pronounced with DME fuel. For the fuels closer to the conventional DF2, the effect of those properties is minimal. The evaporation model includes the behavior of evaporation at high pressure. The rate of evaporation is usually suppressed with higher pressure but at lower temperature than typical engine-like conditions, the effect is inverted. This effect might be significant for the low temperature combustion. Of the two proposed ignition delay models the local model has a slightly better accuracy compared to the global model. The results demonstrate the improvements that can be obtained when additional fuel specific properties are included in the spray ignition model. Although the proposed fuel sensitive combustion model calculates fuel effect to the combustion, the effect of ignition delay to the overall result of engine cycle simulation was much more dominant with given fuels in this study. Advisors/Committee Members: Jung, Dohoy (committee member), Borgnakke, Claus (committee member), Gamba, Mirko (committee member), Boehman, Andre L. (committee member), Assanis, Dionissios N. (committee member).

Subjects/Keywords: Diesel Engine; Quasi-dimensional Multi-zone Simulation; Alternative Fuels; Ignition Delay; Multi-component Evaporation; Spray Model; Mechanical Engineering; Engineering

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APA (6^th Edition):

Kwak, K. H. (2014). Fuel Sensitive Combustion Model Based On Quasi-Dimensional Multi-Zone Approach For Direct Injection Compression Ignition Engines. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/108990

Chicago Manual of Style (16^th Edition):

Kwak, Kyoung Hyun. “Fuel Sensitive Combustion Model Based On Quasi-Dimensional Multi-Zone Approach For Direct Injection Compression Ignition Engines.” 2014. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/108990.

MLA Handbook (7^th Edition):

Kwak, Kyoung Hyun. “Fuel Sensitive Combustion Model Based On Quasi-Dimensional Multi-Zone Approach For Direct Injection Compression Ignition Engines.” 2014. Web. 13 Apr 2021.

Vancouver:

Kwak KH. Fuel Sensitive Combustion Model Based On Quasi-Dimensional Multi-Zone Approach For Direct Injection Compression Ignition Engines. [Internet] [Doctoral dissertation]. University of Michigan; 2014. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/108990.

Council of Science Editors:

Kwak KH. Fuel Sensitive Combustion Model Based On Quasi-Dimensional Multi-Zone Approach For Direct Injection Compression Ignition Engines. [Doctoral Dissertation]. University of Michigan; 2014. Available from: http://hdl.handle.net/2027.42/108990

28. Larimore, Jacob William. Experimental Analysis and Control of Recompression Homogeneous Charge Compression Ignition Combustion at the High Cyclic Variability Limit.

Degree: PhD, Mechanical Engineering, 2014, University of Michigan

URL: http://hdl.handle.net/2027.42/107231

► The automotive industry currently faces many challenges pertaining to strict emissions and fuel consumption constraints for a sustainable society. These regulations have motivated the investigation… (more)

▼ The automotive industry currently faces many challenges pertaining to strict emissions and fuel consumption constraints for a sustainable society. These regulations have motivated the investigation of low temperature combustion modes such as homogeneous charge compression ignition (HCCI) as a potential solution to meet these demands. HCCI combustion is characterized by high efficiency and low engine-out emissions. However, this advanced combustion mode is limited in the speed-load operating space due to high pressure rise rates for increased loads. Often higher loads are run at later combustion phasings to reduce pressure rise rates, however high cyclic variability (CV) can also be a limiting factor for late combustion phasings. This work presents advancements in the understanding of high variability dynamics in recompression HCCI as well as methods for control of CV and load transitions which typically encounter regions of high variability. Standard in-cylinder pressure based analysis methods are extended for use on high variability data. This includes a method of determining the trapped residual mass in real time. Determination of the residual mass is critical in recompression HCCI because of the combustion's sensitivity to the thermal energy contained within the residual charge. Trapping too much or little residuals can lead to ringing or misfires and CV, respectively. Various levels of CV are studied using large experimental data sets to ensure statistical relevance. The cycle resolved analysis of this data has allowed for the development of a predictive model of the variability associated with lean late phasing combustion. This model is used to develop control which can suppress cyclic variability at steady state. Knowledge about steady state control of CV and its oscillatory dynamics is further applied to the development of an adaptive controller. The adaptive controller uses a parameter estimation scheme in the feedforward component of a baseline midranging structure. The adaptive feedforward component enables the ability to correct for modeling errors and reduces parameterization effort. Experimental results demonstrate that the control is effective at navigating through large load transients while avoiding excess amounts of variability. Additionally, the actuators spend more time in a region of high authority when compared to non-adaptive control. Advisors/Committee Members: Stefanopoulou, Anna G. (committee member), Hellstrom, Erik (committee member), Sun, Jing (committee member), Boehman, Andre L. (committee member), Jiang, Li (committee member).

Subjects/Keywords: Homogeneous Charge Compression Ignition; Cyclic Variability; Control Systems; Dynamical Systems; Advanced Combustion; Electrical Engineering; Mechanical Engineering; Engineering

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APA (6^th Edition):

Larimore, J. W. (2014). Experimental Analysis and Control of Recompression Homogeneous Charge Compression Ignition Combustion at the High Cyclic Variability Limit. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/107231

Chicago Manual of Style (16^th Edition):

Larimore, Jacob William. “Experimental Analysis and Control of Recompression Homogeneous Charge Compression Ignition Combustion at the High Cyclic Variability Limit.” 2014. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/107231.

MLA Handbook (7^th Edition):

Larimore, Jacob William. “Experimental Analysis and Control of Recompression Homogeneous Charge Compression Ignition Combustion at the High Cyclic Variability Limit.” 2014. Web. 13 Apr 2021.

Vancouver:

Larimore JW. Experimental Analysis and Control of Recompression Homogeneous Charge Compression Ignition Combustion at the High Cyclic Variability Limit. [Internet] [Doctoral dissertation]. University of Michigan; 2014. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/107231.

Council of Science Editors:

Larimore JW. Experimental Analysis and Control of Recompression Homogeneous Charge Compression Ignition Combustion at the High Cyclic Variability Limit. [Doctoral Dissertation]. University of Michigan; 2014. Available from: http://hdl.handle.net/2027.42/107231

29. Lillo, Peter. Topological Development of Homogeneous-Charge and Stratified-Charge Flames in an Internal Combustion Engine.

Degree: PhD, Mechanical Engineering, 2016, University of Michigan

URL: http://hdl.handle.net/2027.42/135897

► No technology can currently replace fossil fuel powered internal combustion engines as the primary source of transportation power. For better or worse, the next generation… (more)

▼ No technology can currently replace fossil fuel powered internal combustion engines as the primary source of transportation power. For better or worse, the next generation of automobiles will continue to be powered by combustion. As such, it is in our best interest to learn how to burn fuel in the smartest manner. There are many advanced combustion strategies that promise efficiency improvements over conventional strategies, most of which have failed to make it onto the road due to technical deficiencies. Many of these strategies, such as spray-guided stratified-charge combustion, rely upon the precise partial mixing of fuel with oxidizer inside the combustion chamber. Advanced computational tools are being developed to aid such challenging designs. However, a lack of understanding of in-cylinder flame physics and computational power limitations continues to hinder the predictive abilities of engine models. In this work, engine flame topological development is studied. Flame wrinkled-ness is both one of the most important and poorly understood engine combustion phenomena. Generally, a flame may wrinkle for two reasons: (i) its own naturally instabilities and/or (ii) through interaction with turbulent flow. The relative contribution of these two causes towards flame wrinkled-ness in the engine environment was unclear so targeted experiments were performed to provide some clarity. The development of flame wrinkled-ness within an optically accessible engine was measured with a combination of planar laser induced fluorescence and stereo particle image velocimetry under homogeneous-charge and stratified-charge conditions. From this, equivalence ratio, charge velocities, and flame wrinkled-ness were quantified and analyzed. For the iso-octane/toluene mixtures studied the flame wrinkling was insensitive to thermo-diffusive flame front instabilities. The relative contribution of wrinkles of various spatial scales towards overall flame wrinkled-ness was also measured. Homogeneous-charge flames generally had lower wrinkling factors than stratified-charge flames. Overall, flame wrinkled-ness increased with flame size under both modes of engine operation. Large flames demonstrated an ability to maintain more large scale wrinkles than small flames, which contributed to their overall higher levels of wrinkled-ness. Based on the observations, suggestions are provided for those who are developing advanced homogeneous and stratified-charge engine models. Advisors/Committee Members: Sick, Volker (committee member), Driscoll, James F (committee member), Boehman, Andre L (committee member), Martz, Jason Brian (committee member), Reuss, David L (committee member).

Subjects/Keywords: Internal Combustion Engine; Engine Flame Topology; Homogeneous Charge Combustion; Stratified Charge Combustion; Optical Diagnostics; Flame Wrinkling; Mechanical Engineering; Engineering

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APA (6^th Edition):

Lillo, P. (2016). Topological Development of Homogeneous-Charge and Stratified-Charge Flames in an Internal Combustion Engine. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/135897

Chicago Manual of Style (16^th Edition):

Lillo, Peter. “Topological Development of Homogeneous-Charge and Stratified-Charge Flames in an Internal Combustion Engine.” 2016. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/135897.

MLA Handbook (7^th Edition):

Lillo, Peter. “Topological Development of Homogeneous-Charge and Stratified-Charge Flames in an Internal Combustion Engine.” 2016. Web. 13 Apr 2021.

Vancouver:

Lillo P. Topological Development of Homogeneous-Charge and Stratified-Charge Flames in an Internal Combustion Engine. [Internet] [Doctoral dissertation]. University of Michigan; 2016. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/135897.

Council of Science Editors:

Lillo P. Topological Development of Homogeneous-Charge and Stratified-Charge Flames in an Internal Combustion Engine. [Doctoral Dissertation]. University of Michigan; 2016. Available from: http://hdl.handle.net/2027.42/135897

30. Fatouraie, Mohammad. The Effects of Ethanol/Gasoline Blends on Advanced Combustion Strategies in Internal Combustion Engines.

Degree: PhD, Mechanical Engineering, 2014, University of Michigan

URL: http://hdl.handle.net/2027.42/107175

► This dissertation presents the effects of blending ethanol with gasoline on advanced combustion strategies in internal combustion engines. The unique chemical, physical and thermal properties… (more)

▼ This dissertation presents the effects of blending ethanol with gasoline on advanced combustion strategies in internal combustion engines. The unique chemical, physical and thermal properties of ethanol/ gasoline blends can be used to improve the performance and emissions of advanced engine technologies like gasoline direct injection (GDI) also called direct injection spark ignition (DISI), homogenous charge compression ignition (HCCI) and spark assisted homogenous charge compression ignition (SA-HCCI). This work used experimental studies to understand the impact of ethanol and ethanol/gasoline blends on advanced engine strategies and on understanding which of the fundamental properties of ethanol and ethanol blends control engine performance. The technical approach leveraged high speed imaging to study the fuel spray, combustion, ignition, and sooting (where appropriate) properties of the fuels using different optically accessible engine hardware, including HCCI and GDI configurations. The results of the HCCI work indicated stable operating conditions could be extended to leaner mixtures using the ethanol blends, if the effect of charge cooling due to fuel vaporization was anticipated. Ethanol also improved the stability of flame initiation and growth in SA-HCCI, which affected the global autoignition and performance of the engine. The effect of ethanol on these chemically-controlled engine modes was dominated by the impact of the fuel on thermal stratification. Ethanol combustion chemistry appeared to have little impact. Significant reduction in soot formation was observed in the DISI engine studies using ethanol blends compared to a baseline of reference grade gasoline. This was due to combined effects of ethanol on combustion chemistry, where oxygenated fuels suppress the formation of soot precursors, and of ethanol on increasing evaporation and reducing liquid fuel on the piston, where ethanol changed the fuel spray cone angle and spray collapse. In particular, fuel impingement and wetting of the piston surface dominated in-cylinder soot formation, thus the ethanol fuel spray characteristics that reduced interaction of the fuel spray with the piston and enhanced fuel mixing led to less soot formation. Advisors/Committee Members: Wooldridge, Margaret S. (committee member), Kolmanovsky, Ilya Vladimir (committee member), Wooldridge, Steven T. (committee member), Lavoie, George A. (committee member), Boehman, Andre L. (committee member).

Subjects/Keywords: HCCI; ETHANOL; DISI; SOOT; PM; SACI; Mechanical Engineering; Engineering

…33], [34]. At the University of Michigan, Zigler et al. have contributed to… …emission characteristics were performed using two optical engine facilities at the University of… …Michigan. The kinetically controlled combustion studies were performed using a port fuel…

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Fatouraie, M. (2014). The Effects of Ethanol/Gasoline Blends on Advanced Combustion Strategies in Internal Combustion Engines. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/107175

Chicago Manual of Style (16^th Edition):

Fatouraie, Mohammad. “The Effects of Ethanol/Gasoline Blends on Advanced Combustion Strategies in Internal Combustion Engines.” 2014. Doctoral Dissertation, University of Michigan. Accessed April 13, 2021. http://hdl.handle.net/2027.42/107175.

MLA Handbook (7^th Edition):

Fatouraie, Mohammad. “The Effects of Ethanol/Gasoline Blends on Advanced Combustion Strategies in Internal Combustion Engines.” 2014. Web. 13 Apr 2021.

Vancouver:

Fatouraie M. The Effects of Ethanol/Gasoline Blends on Advanced Combustion Strategies in Internal Combustion Engines. [Internet] [Doctoral dissertation]. University of Michigan; 2014. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/2027.42/107175.

Council of Science Editors:

Fatouraie M. The Effects of Ethanol/Gasoline Blends on Advanced Combustion Strategies in Internal Combustion Engines. [Doctoral Dissertation]. University of Michigan; 2014. Available from: http://hdl.handle.net/2027.42/107175

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