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University of Texas – Austin
1.
Chang, Michael Kazuto.
Development of a testing protocol for insulation ignition by wildland fire embers.
Degree: MSin Engineering, Mechanical Engineering, 2017, University of Texas – Austin
URL: http://hdl.handle.net/2152/64118 
► Wildfire embers, also known as firebrands, are one of the dominant fire spread elements in wildfire growth. These embers are associated with the ignition of…
(more)
▼ Wildfire embers, also known as firebrands, are one of the dominant fire spread elements in wildfire growth. These embers are associated with the
ignition of structures at the wildland-urban interface (WUI) and there is effort to understand the mechanisms by which they ignite homes. One of the vulnerable areas of homes at the WUI is the attic space.
The
ignition of attic materials by embers is not a well characterized problem, and so an effort was made to better understand the parameters critical to this issue. This thesis details the assessment of the
ignition processes for embers attacking attic materials. An experimental procedure was developed to create consistent embers of specific sizes with well characterized thermal properties. These embers were transferred to various fuel beds, where air flow conditions were adjusted to determine which conditions would cause the fuel bed to ignite, extinguish, or smolder. The materials tested were extruded polystyrene (XPS), expanded polystyrene (EPS), polyurethane (PUR), flame retarded/non-flame retarded denim, and flame retarded/non-flame retarded cellulose, which are all typical insulation materials found in the attic. The differences between flame retarded and non-flame retarded materials were highlighted through these material comparisons. Two configurations of embers, a single large ember vs. an equivalent mass pile of fragmented embers, were tested. Thermocouples and IR camera recordings were used to monitor fuel bed and ember temperatures, in order to investigate the signatures of
ignition
Once the critical
ignition parameter space was defined, a better understanding of the material properties was required to discern what material features were responsible for the ember flammability observations. In order to accomplish this, simple methodologies for measuring thermal conductivity, specific heat, and density were created. The oxygen consumption (cone) calorimeter was used to determine flammability characteristics of the materials, such as heat release rates and
ignition times, while thermogravimetric analysis was used to define the material degradation behavior. Finally, X-ray diffraction was explored in order to find the presence of flame retardants in the various materials.
Advisors/Committee Members: Ezekoye, Ofodike A. (advisor), Marr, Kevin C (committee member).
Subjects/Keywords: Firebrands; Ignition; Embers; Insulation ignition
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APA (6th Edition):
Chang, M. K. (2017). Development of a testing protocol for insulation ignition by wildland fire embers. (Masters Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/64118
Chicago Manual of Style (16th Edition):
Chang, Michael Kazuto. “Development of a testing protocol for insulation ignition by wildland fire embers.” 2017. Masters Thesis, University of Texas – Austin. Accessed April 18, 2021.
http://hdl.handle.net/2152/64118.
MLA Handbook (7th Edition):
Chang, Michael Kazuto. “Development of a testing protocol for insulation ignition by wildland fire embers.” 2017. Web. 18 Apr 2021.
Vancouver:
Chang MK. Development of a testing protocol for insulation ignition by wildland fire embers. [Internet] [Masters thesis]. University of Texas – Austin; 2017. [cited 2021 Apr 18].
Available from: http://hdl.handle.net/2152/64118.
Council of Science Editors:
Chang MK. Development of a testing protocol for insulation ignition by wildland fire embers. [Masters Thesis]. University of Texas – Austin; 2017. Available from: http://hdl.handle.net/2152/64118
2.
Parameshwara, Vikram.
Numerical study of autoignition of fuel-air mixtures at elevated temperatures and pressures
.
Degree: Chalmers tekniska högskola / Institutionen för mekanik och maritima vetenskaper, 2021, Chalmers University of Technology
URL: http://hdl.handle.net/20.500.12380/302265
► In a conventional spark-ignition (SI) engine the fuel-air mixture is injected into the cylinder where it is mixed with the residual gasses and compressed. Under…
(more)
▼ In a conventional spark-ignition (SI) engine the fuel-air mixture is injected into the cylinder where it is mixed with the residual gasses and compressed. Under normal operation, combustion takes place at the end of the compression stroke, the mixture is ignited by a spark, flame kernel grows, turbulent flame develops and propagates to the walls where it is quenched. As we strive for better thermal efficiency, the compression ratio is the ideal parameter to increase. However, a phenomenon called knock occurs at elevated temperatures and pressures and impedes the improvements to thermal efficiency by simply increasing the compression ratio. Knock occurs because of auto-ignition initiated locally in hot spots in the unburnt fuel-air mixture ahead of the advancing flame front. It deteriorates the working characteristics of the engine and drastically reduces its durability.
Previously, most of the research into knock was carried out experimentally. The recent developments in computer hardware, software, and dedicated chemical kinetic mechanisms that can accurately model the behaviour of gasoline have made it possible to calculate the autoignition of fuels with acceptable accuracy. The main objective of this project is to study the autoignition behaviour of various fuel-air mixtures at elevated temperatures and pressures using the aforementioned chemical kinetic mechanisms.
The autoignition of commercially available fuels is the focus of this thesis. The chemical kinetic mechanisms chosen are from RWTH Aachen University, King Abdullah University of Science, and Technology and Lawrence Livermore National Laboratory. Using the software CHEMKIN-Pro, these mechanisms are adopted to simulate the ignition delay times of iso-octane, n-heptane, and primary reference fuel blended with ethanol (PRF-E) at various temperatures, pressures, and equivalence ratios (fuel-air ratio). The calculated values of ignition delay times are compared with the experimental data available for the same input parameters and the chemical mechanisms from Aachen university is chosen based on the accuracy of the results and the speed of computations.
Using the selected mechanism, ignition delay times for E10 (fuel of RON95 with 10% ethanol by volume), 95 unleaded (RON95), and 98 unleaded (RON98) are calculated. The knock prediction model by Kalghatgi et al., 2017 is used as the criterion for suggesting the best operating range temperature range of the fuels to avoid knock in an engine. Using MATLAB and Excel, graphs for the calculated ignition delay times vs temperature are plotted to study the dependence of various input parameters (temperature, pressure, equivalence ratio, and fuel composition).
The following results are observed:
• The ignition delay times reduce with an increase in the input pressure at a particular temperature.
• The ignition delay times decrease with an increase in equivalence ratio (ϕ).
• The knock resistance of a fuel increases with an increase in the RON of a fuel.
• The ignition delay times reduce with an increase in…
Subjects/Keywords: Knock;
Auto-ignition;
Ignition delay
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APA (6th Edition):
Parameshwara, V. (2021). Numerical study of autoignition of fuel-air mixtures at elevated temperatures and pressures
. (Thesis). Chalmers University of Technology. Retrieved from http://hdl.handle.net/20.500.12380/302265
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Parameshwara, Vikram. “Numerical study of autoignition of fuel-air mixtures at elevated temperatures and pressures
.” 2021. Thesis, Chalmers University of Technology. Accessed April 18, 2021.
http://hdl.handle.net/20.500.12380/302265.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Parameshwara, Vikram. “Numerical study of autoignition of fuel-air mixtures at elevated temperatures and pressures
.” 2021. Web. 18 Apr 2021.
Vancouver:
Parameshwara V. Numerical study of autoignition of fuel-air mixtures at elevated temperatures and pressures
. [Internet] [Thesis]. Chalmers University of Technology; 2021. [cited 2021 Apr 18].
Available from: http://hdl.handle.net/20.500.12380/302265.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Parameshwara V. Numerical study of autoignition of fuel-air mixtures at elevated temperatures and pressures
. [Thesis]. Chalmers University of Technology; 2021. Available from: http://hdl.handle.net/20.500.12380/302265
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Nelson Mandela Metropolitan University
3.
Wodausch, Jens.
Investigation and prediction of autoignition during hot start conditions.
Degree: Faculty of Engineering, the Built Environment and Information Technology, 2009, Nelson Mandela Metropolitan University
URL: http://hdl.handle.net/10948/991
► This Master’s thesis discusses the investigation of autoignition (knock) of air-fuel mixtures in internal combustion engines (type EA 827; 1.6 and 1.4 l) under hot…
(more)
▼ This Master’s thesis discusses the investigation of autoignition (knock) of air-fuel mixtures in internal combustion engines (type EA 827; 1.6 and 1.4 l) under hot start conditions. Chapter Three comprehensively reviews literature on fuel characteristics; specifically boiling point, chemistry and the difference between the Research and Motor Octane Number (RON and MON). Furthermore different types of autoignition are discussed with regards to their detection and assessment in the chapter. The subsection on engine management looks at possible methods of altering and eliminating autoignition. Chapter Four details the equipment used to obtain data and measurements, as well as the signal conditioning of the spark and injector signal. Chapter Five discusses the actual results obtained during summer testing of the different methods of altering and eliminating autoignition in an internal combustion engine, as derived from the theories presented in Chapter Three. The summer tests finally verified the new application level and showed that only a reduction in the quantity of fuel injected can eliminate autoignition. However, a slight decrease in heat release does cause an increase in start time. In Chapter Six, based on the test results, a simulation model which calculates the probability of autoignition in a 1.4 l (Econo) engine during hot start conditions in Matlab/Simulink was developed. This simulation model satisfactorily verified test results.
Subjects/Keywords: Automobiles – Ignition
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APA (6th Edition):
Wodausch, J. (2009). Investigation and prediction of autoignition during hot start conditions. (Thesis). Nelson Mandela Metropolitan University. Retrieved from http://hdl.handle.net/10948/991
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Wodausch, Jens. “Investigation and prediction of autoignition during hot start conditions.” 2009. Thesis, Nelson Mandela Metropolitan University. Accessed April 18, 2021.
http://hdl.handle.net/10948/991.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Wodausch, Jens. “Investigation and prediction of autoignition during hot start conditions.” 2009. Web. 18 Apr 2021.
Vancouver:
Wodausch J. Investigation and prediction of autoignition during hot start conditions. [Internet] [Thesis]. Nelson Mandela Metropolitan University; 2009. [cited 2021 Apr 18].
Available from: http://hdl.handle.net/10948/991.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Wodausch J. Investigation and prediction of autoignition during hot start conditions. [Thesis]. Nelson Mandela Metropolitan University; 2009. Available from: http://hdl.handle.net/10948/991
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Georgia Tech
4.
Wei, Sheng.
Effect of jet fuel composition on forced ignition in gas turbine combustors.
Degree: PhD, Aerospace Engineering, 2019, Georgia Tech
URL: http://hdl.handle.net/1853/61204
► The rapid growth in the aviation industry means increasing consumption of jet fuels, which is leading to greater interest in alternate and sustainable fuel sources.…
(more)
▼ The rapid growth in the aviation industry means increasing consumption of jet fuels, which is leading to greater interest in alternate and sustainable fuel sources. The overall properties of these alternative fuels can be designed to meet existing standards. Nevertheless, the compositional differences between alternative and conventional fuels can lead to important variations in chemical and physical properties that impact engine performance. For example,
ignition is of paramount importance to ensure reliable operation, especially in extreme conditions like cold starts and high altitude relights. For aircraft engines,
ignition is the process of creating self-sustaining flames starting with a high-temperature source located near a combustor liner. This thesis is devoted to studying the differences in
ignition behavior due to the variations in fuel composition. Fuel variations in
ignition are studied in a well-characterized test facility that is readily amenable to modeling and simulation. The experiments employ a sunken-fire ignitor, like those typically employed in aircraft engines, operating at 15 Hz with ~1.25J spark energy. Performance differences among fuels are characterized through their
ignition probabilities. To understand both the chemical and physical fuel effects on
ignition, both prevaporized fuels and liquid fuel sprays are examined. The purpose of prevaporizing the fuel is to remove the process of liquid to gas transition and to focus on combustion chemistry alone. In the forced
ignition of liquid fuel sprays, which mimics the situation encountered in aviation gas turbine engines, both physical and chemical properties of the fuel are relevant. Statistically significant differences between fuel
ignition probabilities are observed. The droplet heating time is shown to correlate well with
ignition probability. A particle Doppler phase analyzer (PDPA) is used to study droplet size distribution near the ignitor. These droplet distribution measurements can be useful for future CFD modeling. In addition to differentiating fuel performances through
ignition probability, advanced diagnostic techniques are employed to understand the evolution of a spark kernels as it interacts with combustible mixtures. These techniques include high speed OH planar laser induced fluorescence, OH* chemiluminescence, and schlieren imaging. The results reveal the entrainment of ambient fluid into the convecting spark kernel, the decomposition of vaporized jet fuel in the high temperature kernel, and the transition from local “hot spots” within the spark kernel to a self-sustaining flame. In addition to the experiments, reduced order modeling is used to better understand the physics and chemistry of
ignition for both prevaporized and liquid fuels. Chemical differences are found to depend on the relative distribution between intermediate breakdown products (e.g., ethylene, propene and isobutene) from the parent fuels, as these intermediates have drastically different chemical rates as a function of temperature. The energy transfer…
Advisors/Committee Members: Seitzman, Jerry (advisor), Jagoda, Jechiel (committee member), Sun, Wenting (committee member), Oefelein, Joseph (committee member), Ranjan, Devesh (committee member).
Subjects/Keywords: Ignition; Combustion
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APA (6th Edition):
Wei, S. (2019). Effect of jet fuel composition on forced ignition in gas turbine combustors. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/61204
Chicago Manual of Style (16th Edition):
Wei, Sheng. “Effect of jet fuel composition on forced ignition in gas turbine combustors.” 2019. Doctoral Dissertation, Georgia Tech. Accessed April 18, 2021.
http://hdl.handle.net/1853/61204.
MLA Handbook (7th Edition):
Wei, Sheng. “Effect of jet fuel composition on forced ignition in gas turbine combustors.” 2019. Web. 18 Apr 2021.
Vancouver:
Wei S. Effect of jet fuel composition on forced ignition in gas turbine combustors. [Internet] [Doctoral dissertation]. Georgia Tech; 2019. [cited 2021 Apr 18].
Available from: http://hdl.handle.net/1853/61204.
Council of Science Editors:
Wei S. Effect of jet fuel composition on forced ignition in gas turbine combustors. [Doctoral Dissertation]. Georgia Tech; 2019. Available from: http://hdl.handle.net/1853/61204
King Abdullah University of Science and Technology
5.
mubarak ali, mohammed jaasim.
Modeling of Pre-ignition and Super-knock in Spark Ignition Engines.
Degree: Physical Science and Engineering (PSE) Division, 2018, King Abdullah University of Science and Technology
URL: http://hdl.handle.net/10754/628315
► Advanced combustion concepts are required to meet the increasing global energy demand and stringent emission regulations imposed by the governments on automobile manufacturers. Improvement in…
(more)
▼ Advanced combustion concepts are required to meet the increasing global energy demand and stringent emission regulations imposed by the governments on automobile manufacturers. Improvement in efficiency and reduction in emissions can be achieved by downsizing the Spark
Ignition (SI) engines. The operating range of SI engine is limited by occurrence of knock, pre-
ignition and the following super-knock due to boosting of intake pressure, to account for the reduction of power, as a result of downsizing the engine. Super-knock, which represents high momentary pressure accompanied with pressure oscillations, is known to permanently damage the moving component of the engines. Therefore fundamental comprehensive understanding of the mechanism involved in pre-
ignition and super-knock are required to design highly efficient spark
ignition engines with lower emissions that can meet the increasing government regulations.
\nThe thesis focuses on auto-
ignition characteristics of endgas and the bulk mixture properties that favor transition of pre-
ignition to super-knock. Direct numerical studies indicate that super-knock occurs to due to initiation of premature flame front that transition into detonation. In literature, many sources are reported to trigger pre-
ignition. Due to the uncertainty of the information on the sources that trigger pre-
ignition, it is extremely difficult to predict and control pre-
ignition event in SI engines. Since the information on the source of pre-
ignition is not available, the main focus of this work is to understand the physical and chemical mechanisms involved in super-knock, factors that influence super-knock and methods to predict super-knock.
\n
Pre-
ignition was initiated at known locations and crank angle using a hotspot of known size and strength. Different parametric cases were studied and the location and timing of pre-
ignition initiation is found to be extremely important in determining the transition of pre-
ignition event to super-knock. Pre-
ignition increases the temperature of the endgas and the overall bulk mixture, that transitions the pre-
ignition flame front to a detonation. The transition of the flame propagation mode from deflagration to detonation was investigated with different type of analysis methods and all results confirmed the transition of pre-
ignition flame front to detonation that results in super- knock.
Advisors/Committee Members: Im, Hong G. (advisor), Johansson, Bengt (committee member), Sarathy, Mani (committee member), Sun, Shuyu (committee member), Rutland, Christopher (committee member).
Subjects/Keywords: super-knock; pre-ignition; sequential auto-ignition
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APA (6th Edition):
mubarak ali, m. j. (2018). Modeling of Pre-ignition and Super-knock in Spark Ignition Engines. (Thesis). King Abdullah University of Science and Technology. Retrieved from http://hdl.handle.net/10754/628315
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
mubarak ali, mohammed jaasim. “Modeling of Pre-ignition and Super-knock in Spark Ignition Engines.” 2018. Thesis, King Abdullah University of Science and Technology. Accessed April 18, 2021.
http://hdl.handle.net/10754/628315.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
mubarak ali, mohammed jaasim. “Modeling of Pre-ignition and Super-knock in Spark Ignition Engines.” 2018. Web. 18 Apr 2021.
Vancouver:
mubarak ali mj. Modeling of Pre-ignition and Super-knock in Spark Ignition Engines. [Internet] [Thesis]. King Abdullah University of Science and Technology; 2018. [cited 2021 Apr 18].
Available from: http://hdl.handle.net/10754/628315.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
mubarak ali mj. Modeling of Pre-ignition and Super-knock in Spark Ignition Engines. [Thesis]. King Abdullah University of Science and Technology; 2018. Available from: http://hdl.handle.net/10754/628315
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Victoria
6.
Pitt, Philip Lawrence.
The early phase of spark ignition.
Degree: Department of Physics and Astronomy, 2018, University of Victoria
URL: https://dspace.library.uvic.ca//handle/1828/9664
► In this dissertation, some practical ignition techniques are presented that show how some problems of lean-burn combustion can be overcome. Then, to shed light on…
(more)
▼ In this dissertation, some practical
ignition techniques are presented that show how some problems of lean-burn combustion can be overcome. Then, to shed light on the effects of the
ignition techniques described, the focus shifts to the more specific problem of the early phase of spark
ignition. Thermal models of
ignition are reviewed. These models treat the energy provided by the electrical discharge as a point source, delivered infinitely fast and creating a spherically symmetric
ignition kernel. The thesis challenges the basis of these thermal models by reviewing the work of many investigators who have clearly shown that the temporal characteristics of the discharge have a profound effect upon
ignition. Photographic evidence of the early phase of
ignition, as well as other evidence from the literature, is also presented. The evidence clearly demonstrates that the morphology of spark kernels in the early phase of development is toroidal, not spherical as suggested by thermal models. A new perspective for
ignition, a fluid dynamic point of view, is described. The common
ignition devices are then classified according to fluid dynamics. A model describing the behaviour of spark kernels is presented, which extends a previously established mixing model for plasma jets, to the realm of conventional axial discharges. Comparison of the model behaviour to some limited data is made. The model is modified by including the effect of heat addition from combustion, and
ignition criteria are discussed.
Advisors/Committee Members: Clements, R. M. (supervisor).
Subjects/Keywords: Spark ignition engines
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APA (6th Edition):
Pitt, P. L. (2018). The early phase of spark ignition. (Thesis). University of Victoria. Retrieved from https://dspace.library.uvic.ca//handle/1828/9664
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Pitt, Philip Lawrence. “The early phase of spark ignition.” 2018. Thesis, University of Victoria. Accessed April 18, 2021.
https://dspace.library.uvic.ca//handle/1828/9664.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Pitt, Philip Lawrence. “The early phase of spark ignition.” 2018. Web. 18 Apr 2021.
Vancouver:
Pitt PL. The early phase of spark ignition. [Internet] [Thesis]. University of Victoria; 2018. [cited 2021 Apr 18].
Available from: https://dspace.library.uvic.ca//handle/1828/9664.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Pitt PL. The early phase of spark ignition. [Thesis]. University of Victoria; 2018. Available from: https://dspace.library.uvic.ca//handle/1828/9664
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Delft University of Technology
7.
Dickert, Zoe (author).
GOX-Ethanol Resonance Ignition System Design: Design and Modeling of the Gas Dynamic Heating in a GOX-Ethanol Resonance Ignition Device.
Degree: 2020, Delft University of Technology
URL: http://resolver.tudelft.nl/uuid:76d058ab-c0d8-40dc-a22b-83c6bda0db2f
► Resonance ignition devices utilize the gas dynamic phenomenon to heat propellant gases to their auto-ignition temperature in order to initiate combustion. These devices are a…
(more)
▼ Resonance ignition devices utilize the gas dynamic phenomenon to heat propellant gases to their auto-ignition temperature in order to initiate combustion. These devices are a promising alternative to current rocket engine ignition systems. In this thesis a python code was developed to generate a resonance ignition system design. The design was tested and parameters characterized using ANSYS Fluent. This resulted in a detailed design of a GOX-Ethanol resonance ignition device that is successful in heating the resonance gas to above its auto-ignition temperature. This project presents the python and Fluent tools developed to conduct this study, analyses the effect of different input parameters on the device, and presents a working detailed design.
Aerospace Engineering
Advisors/Committee Members: Zandbergen, B.T.C. (mentor), Cervone, A. (graduation committee), van Zuijlen, A.H. (graduation committee), Delft University of Technology (degree granting institution).
Subjects/Keywords: ignition; resonance; ethanol
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APA (6th Edition):
Dickert, Z. (. (2020). GOX-Ethanol Resonance Ignition System Design: Design and Modeling of the Gas Dynamic Heating in a GOX-Ethanol Resonance Ignition Device. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:76d058ab-c0d8-40dc-a22b-83c6bda0db2f
Chicago Manual of Style (16th Edition):
Dickert, Zoe (author). “GOX-Ethanol Resonance Ignition System Design: Design and Modeling of the Gas Dynamic Heating in a GOX-Ethanol Resonance Ignition Device.” 2020. Masters Thesis, Delft University of Technology. Accessed April 18, 2021.
http://resolver.tudelft.nl/uuid:76d058ab-c0d8-40dc-a22b-83c6bda0db2f.
MLA Handbook (7th Edition):
Dickert, Zoe (author). “GOX-Ethanol Resonance Ignition System Design: Design and Modeling of the Gas Dynamic Heating in a GOX-Ethanol Resonance Ignition Device.” 2020. Web. 18 Apr 2021.
Vancouver:
Dickert Z(. GOX-Ethanol Resonance Ignition System Design: Design and Modeling of the Gas Dynamic Heating in a GOX-Ethanol Resonance Ignition Device. [Internet] [Masters thesis]. Delft University of Technology; 2020. [cited 2021 Apr 18].
Available from: http://resolver.tudelft.nl/uuid:76d058ab-c0d8-40dc-a22b-83c6bda0db2f.
Council of Science Editors:
Dickert Z(. GOX-Ethanol Resonance Ignition System Design: Design and Modeling of the Gas Dynamic Heating in a GOX-Ethanol Resonance Ignition Device. [Masters Thesis]. Delft University of Technology; 2020. Available from: http://resolver.tudelft.nl/uuid:76d058ab-c0d8-40dc-a22b-83c6bda0db2f
Michigan State University
8.
Chinnathambi, Prasanna.
Experiments on the effects of dilution and fuel composition on ignition of gasoline and alternative fuels in a rapid compression machine.
Degree: 2019, Michigan State University
URL: http://etd.lib.msu.edu/islandora/object/etd:48224
► Thesis Ph. D. Michigan State University. Mechanical Engineering 2019.
In the first part of this work, ignition of methane-air mixtures under excess air dilution is…
(more)
▼ Thesis Ph. D. Michigan State University. Mechanical Engineering 2019.
In the first part of this work, ignition of methane-air mixtures under excess air dilution is studied. When excess air is used in SI engine operation, thermal efficiency is increased due to increase in compression ratio together with reduced pumping and heat loses. However, stable operation with excess air is challenging due to poor flammability of the resulting diluted mixture. Hence in order to achieve stable and complete combustion a turbulent jet ignition (TJI) system is used to improve combustion of lean methane-air mixtures. Various nozzle designs and operating strategies for a TJI system were tested in a rapid compression machine. 10-90% burn duration measurements were useful in assessing the performance of the nozzle designs while the 0-10% burn durations indicated if optimal air-fuel ratio is achieved within the pre-chamber at the time of ignition. The results indicated that distributed-jets TJI system offered faster and stable combustion while the concentrated-jets TJI system offered better dilution tolerance.Knock in a SI engine occurs due to autoignition of the end gas mixture and typically occurs in the negative temperature coefficient (NTC) region of the fuel-air mixture. Dilution of intake charge with cold exhaust recirculation gases (EGR) reduces combustion temperatures and decreases mixture reactivity thereby reducing knocking tendency. This enables optimal spark timings to be used, thereby increasing efficiency of SI engines which would otherwise be knock limited. Effect of cold EGR dilution is studied in the RCM by measuring the autoignition delay times of gasoline and gasoline surrogate mixtures diluted with varying levels of CO2. The autoignition experiments in the RCM were performed using a novel direct test chamber (DTC) charge preparation approach. The DTC approach enabled mixture preparation directly within the combustion chamber and eliminated the need for mixing tanks. Effect of CO2 dilution in retarding the autoignition delay times was more pronounced in the NTC region, while it was weaker in the low temperature and high temperature regions. The retarding effect was found to be dependent on both the octane number and the fuel composition of the gasoline being studied.Finally, the effect of substituting ethanol(biofuel) in gasoline surrogates for up to 40% by volume is studied. Ethanol is an octane booster, but it blends antagonistically with aromatics such as toluene and synergistically with alkanes with respect to the resulting octane number of the blends. In order to study this blending effect, two gasoline surrogates containing only alkanes (PRF), and alkanes with large amounts of toluene (TRF) are blended with varying levels of ethanol. The ignition delay times of the resulting mixtures are measured in a rapid compression machine and kinetic analysis was carried out using numerical simulations. The kinetic analysis revealed that ethanol controlled the final stages of ignition for the PRF blends when more than 10%…
Advisors/Committee Members: Toulson, Elisa, Lira, Carl, Jaberi, Farhad, Wickman, Indrek.
Subjects/Keywords: Spark ignition engines – Ignition; Spark ignition engines – Alternative fuels; Mechanical engineering
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APA (6th Edition):
Chinnathambi, P. (2019). Experiments on the effects of dilution and fuel composition on ignition of gasoline and alternative fuels in a rapid compression machine. (Thesis). Michigan State University. Retrieved from http://etd.lib.msu.edu/islandora/object/etd:48224
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Chinnathambi, Prasanna. “Experiments on the effects of dilution and fuel composition on ignition of gasoline and alternative fuels in a rapid compression machine.” 2019. Thesis, Michigan State University. Accessed April 18, 2021.
http://etd.lib.msu.edu/islandora/object/etd:48224.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Chinnathambi, Prasanna. “Experiments on the effects of dilution and fuel composition on ignition of gasoline and alternative fuels in a rapid compression machine.” 2019. Web. 18 Apr 2021.
Vancouver:
Chinnathambi P. Experiments on the effects of dilution and fuel composition on ignition of gasoline and alternative fuels in a rapid compression machine. [Internet] [Thesis]. Michigan State University; 2019. [cited 2021 Apr 18].
Available from: http://etd.lib.msu.edu/islandora/object/etd:48224.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Chinnathambi P. Experiments on the effects of dilution and fuel composition on ignition of gasoline and alternative fuels in a rapid compression machine. [Thesis]. Michigan State University; 2019. Available from: http://etd.lib.msu.edu/islandora/object/etd:48224
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Purdue University
9.
De, Narendra Nath.
PHOTOFLASH AND LASER IGNITION OF HIGH-NITROGEN MATERIALS.
Degree: MSin Aeronautics and Astronautics, Aeronautics and Astronautics, 2015, Purdue University
URL: https://docs.lib.purdue.edu/open_access_theses/1053
► Gas-producing energetic materials that can be readily ignited with a photoflash are typically opaque sensitive primary explosives. This study explores the photoactivity of select high-nitrogen…
(more)
▼ Gas-producing energetic materials that can be readily ignited with a photoflash are typically opaque sensitive primary explosives. This study explores the photoactivity of select high-nitrogen (HiN) compounds that are much less sensitive than primary explosives. These HiN materials produce large amounts of gas upon decomposition. This makes them suitable for use in actuators, igniters, or micro-thrusters. Detailed
Ignition studies were conducted using similar shaped pulses at two different wavelength ranges; specifically using a xenon photoflash and a single wavelength CO2 laser. Several select HiN materials were tested for flash ignitability, and those that were found to be flash ignitable were further ignited with CO2 laser heating. By comparing
ignition behavior at various laser and flash intensities, some
ignition mechanisms are suggested. Thermal heating, regardless of source, appears to be the dominant mechanism responsible for
ignition and photochemical effects appear to be negligible in the
ignition of the materials considered in this study. Higher laser and photoflash irradiance is shown to require less energy, and is therefore more efficient. The opacity of the material is an important consideration in ignitability, but not a sufficient criteria. Opaque materials that successfully propagate well in small capillary tubes are seen to be more likely to successfully flash ignite. It is suggested that this is due to the higher burning rate of these materials and also in part to the exothermic reaction occurring at or near the burning surface, rather than further from the burning surface. Both of these characteristics better allow reaction to proceed without quenching and will lead both to more successful microchannel combustion and flash/laser
ignition.
Advisors/Committee Members: Steven F Son, Ibrahim E Gunduz, Li Qiao.
Subjects/Keywords: flash ignition; gas generators; high-nitrogen materials; laser ignition; non-contact ignition; photochemical effects
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APA (6th Edition):
De, N. N. (2015). PHOTOFLASH AND LASER IGNITION OF HIGH-NITROGEN MATERIALS. (Thesis). Purdue University. Retrieved from https://docs.lib.purdue.edu/open_access_theses/1053
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
De, Narendra Nath. “PHOTOFLASH AND LASER IGNITION OF HIGH-NITROGEN MATERIALS.” 2015. Thesis, Purdue University. Accessed April 18, 2021.
https://docs.lib.purdue.edu/open_access_theses/1053.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
De, Narendra Nath. “PHOTOFLASH AND LASER IGNITION OF HIGH-NITROGEN MATERIALS.” 2015. Web. 18 Apr 2021.
Vancouver:
De NN. PHOTOFLASH AND LASER IGNITION OF HIGH-NITROGEN MATERIALS. [Internet] [Thesis]. Purdue University; 2015. [cited 2021 Apr 18].
Available from: https://docs.lib.purdue.edu/open_access_theses/1053.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
De NN. PHOTOFLASH AND LASER IGNITION OF HIGH-NITROGEN MATERIALS. [Thesis]. Purdue University; 2015. Available from: https://docs.lib.purdue.edu/open_access_theses/1053
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Wayne State University
10.
Joshi, Umashankar M.
Quantification Of Auto-Ignition In Diesel Engines.
Degree: PhD, Mechanical Engineering, 2015, Wayne State University
URL: https://digitalcommons.wayne.edu/oa_dissertations/1341
► Efforts have been made previously by researchers to quantify the auto-ignition quality of fuels by calculating global activation energy using Arrhenius plots with data…
(more)
▼ Efforts have been made previously by researchers to quantify the auto-
ignition quality of fuels by calculating global activation energy using Arrhenius plots with data measured for the
ignition delay period (ID). Large variation in the activation energy of fuels has been observed even for fuels with closer CN values. More recently, the activation energy values obtained by Kook et al in (2005) on an optical engine do not agree with data obtained in an identical metallic engine by Jayakumar using fuels of same CN.
The disparity in their results can be attributed to the differences in
ignition delay (ID) and effective temperature definitions used. Most researchers agree upon the start of ID time as the start of injection (SOI). The main point of disagreement has been in defining the end of ID period which is considered to be the start of combustion (SOC). As a result, numerous definitions for the ID period have been used by researchers which lead to variation in calculation of activation energy value. In addition, in heterogeneous combustion equipment to account for changes in charge temperature due to fuel evaporation and piston movement (in engines) an effective temperature value is used. Different definitions for the effective temperature have been reported in the literature. This leads to more variations in the activation energy value calculation. Furthermore, it was observed that engine test conditions and the temperature regime in which the tests are done would also affect the calculation of activation energy value.
This dissertation examines the effects of
ignition delay definitions, effective temperatures, engine conditions and temperature regimes on the global activation energy. Moreover, homogeneous charge test data has shown presence of a NTC regime in which the activation energy value can be either positive, negative or zero. However, heterogeneous test data from literature has always shown positive values for activation energy. This dissertation has also explained the reasons behind such a behavior.
Advisors/Committee Members: Naeim A. Henein.
Subjects/Keywords: Activation energy; Arrhenius plots; Auto-ignition; Diesel combustion; Ignition delay; Ignition delay correlation; Mechanical Engineering
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APA (6th Edition):
Joshi, U. M. (2015). Quantification Of Auto-Ignition In Diesel Engines. (Doctoral Dissertation). Wayne State University. Retrieved from https://digitalcommons.wayne.edu/oa_dissertations/1341
Chicago Manual of Style (16th Edition):
Joshi, Umashankar M. “Quantification Of Auto-Ignition In Diesel Engines.” 2015. Doctoral Dissertation, Wayne State University. Accessed April 18, 2021.
https://digitalcommons.wayne.edu/oa_dissertations/1341.
MLA Handbook (7th Edition):
Joshi, Umashankar M. “Quantification Of Auto-Ignition In Diesel Engines.” 2015. Web. 18 Apr 2021.
Vancouver:
Joshi UM. Quantification Of Auto-Ignition In Diesel Engines. [Internet] [Doctoral dissertation]. Wayne State University; 2015. [cited 2021 Apr 18].
Available from: https://digitalcommons.wayne.edu/oa_dissertations/1341.
Council of Science Editors:
Joshi UM. Quantification Of Auto-Ignition In Diesel Engines. [Doctoral Dissertation]. Wayne State University; 2015. Available from: https://digitalcommons.wayne.edu/oa_dissertations/1341
The Ohio State University
11.
Iqbal, Asim.
Fundamentals of Knock.
Degree: PhD, Mechanical Engineering, 2012, The Ohio State University
URL: http://rave.ohiolink.edu/etdc/view?acc_num=osu1338146766
► In view of the declining global oil reserves and the environmental concerns associated with automotive emissions, it is imperative to improve the fuel efficiency of…
(more)
▼ In view of the declining global oil reserves and the
environmental concerns associated with automotive emissions, it is
imperative to improve the fuel efficiency of engines. Using higher
compression ratios or boosting the specific output through
turbocharging are proven strategies to accomplish this goal.
However, the ability to achieve elevated peak pressures required by
either mechanism to be effective is limited by knock. The lack of
understanding of knock also hinders the realization of potential
benefits of homogeneous charge compression
ignition, a promising
technology that relies on controlled autoignition. Thus, knock is
one of the most serious obstacles in the development of fuel
efficient engines. For this reason, the phenomenon of knock has
been studied extensively, but even after more than a century of
mostly experimental research, the basic mechanism governing knock
remains poorly understood. In order to develop a fundamental
understanding of engine knock, detailed chemical kinetic modeling
of the hydrocarbon oxidation mechanism associated with the
autoignition process is conducted in CHEMKIN (a chemical kinetics
software). Based on the insight gained from kinetic modeling, some
of the key reactions and species that are instrumental to the
autoignition of hydrocarbons are identified. The sensitivity of
knock to various parameters including inlet pressure, inlet
temperature, compression ratio, wall temperature, fuel-air
equivalence ratio, and exhaust gas recirculation (EGR) is examined
through CHEMKIN simulations.
Ignition delay predictions for the
autoignition of a toluene reference fuel (TRF) blend with an
antiknock index of 91 (TRF 91), obtained through extensive chemical
kinetic modeling in CHEMKIN for a constant volume reactor, are used
to develop an improved
ignition delay correlation for predicting
knock in spark
ignition (SI) engines. In addition to NOx control,
EGR is increasingly being utilized for managing combustion phasing
in SI engines to mitigate knock. Therefore, along with other
operating parameters, the effects of EGR on autoignition are
incorporated into the correlation to address the need for
predicting
ignition delay in SI engines operating with EGR. The
modeling approach adopted for TRF 91 is then extended to develop an
ignition delay correlation for an oxygenated surrogate fuel blend
of 87 octane gasoline (with 10% ethanol). In addition, a
conceptually new approach based on multiple timescales is developed
to predict
ignition delay for the autoignition of a primary
reference fuel blend. Finally, the new
ignition delay correlation
for TRF 91 is implemented into the engine simulation tool GT-POWER
and engine dynamometer experiments with knocking combustion are
conducted to validate the knock predictions from the correlation.
Comparison of knock onset predictions from GT-POWER with engine
experiments illustrates the accuracy of the TRF 91
ignition delay
correlation. Hence, the contributions of the present study include
an enhanced understanding of the underlying physics governing…
Advisors/Committee Members: Selamet, Ahmet (Advisor).
Subjects/Keywords: Mechanical Engineering; Knock; Spark Ignition Engines; Combustion; Ignition Delay; Kinetics; Ignition Delay Correlation
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APA (6th Edition):
Iqbal, A. (2012). Fundamentals of Knock. (Doctoral Dissertation). The Ohio State University. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=osu1338146766
Chicago Manual of Style (16th Edition):
Iqbal, Asim. “Fundamentals of Knock.” 2012. Doctoral Dissertation, The Ohio State University. Accessed April 18, 2021.
http://rave.ohiolink.edu/etdc/view?acc_num=osu1338146766.
MLA Handbook (7th Edition):
Iqbal, Asim. “Fundamentals of Knock.” 2012. Web. 18 Apr 2021.
Vancouver:
Iqbal A. Fundamentals of Knock. [Internet] [Doctoral dissertation]. The Ohio State University; 2012. [cited 2021 Apr 18].
Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1338146766.
Council of Science Editors:
Iqbal A. Fundamentals of Knock. [Doctoral Dissertation]. The Ohio State University; 2012. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1338146766
12.
Techer, Anthony.
Simulation aux grandes échelles implicite et explicite de la combustion supersonique : Implicit and Explicit Large-Eddy Simulation of Supersonic Combustion.
Degree: Docteur es, Energétique, thermique, combustion, 2017, Chasseneuil-du-Poitou, Ecole nationale supérieure de mécanique et d'aérotechnique
URL: http://www.theses.fr/2017ESMA0020
► Cette Thèse de doctorat est consacrée à l’étude, par simulation aux grandes échelles ou LES (Larg eeddy simulation), d’un jet pariétal d’hydrogène sous-détendu dans un…
(more)
▼ Cette Thèse de doctorat est consacrée à l’étude, par simulation aux grandes échelles ou LES (Larg eeddy simulation), d’un jet pariétal d’hydrogène sous-détendu dans un écoulement transverse supersonique d’air vicié. Cette configuration est représentative des conditions d’écoulement rencontrées dans les moteurs aérobies de type super-statoréacteurs (scramjets). En effet, les futurs systèmes de transport à grande vitesse dépendent fortement du développement de ce type de moteur. Dans de telles conditions, l’écoulement d’air chaud est maintenu supersonique dans la chambre de combustion afin de réduire les effets induits par l’échauffement et la dissociation de l’air. Nous étudions les processus de mélange et de combustion qui se développent en aval du jet de combustible. Ce travail s’appuie sur l’emploi d’un outil de simulation numérique haute fidélité : CREAMS (Compressible REActive Multi-species Solver) développé à l’Institut Pprime. Ce code de calcul met en oeuvre des schémas numériques d’ordre élevé : schéma Runge–Kutta d’ordre 3 pour l’intégration temporelle combiné à un schéma WENO d’ordre 7 et centré d’ordre 8 pour la discrétisation spatiale. Les simulations réalisées dans des conditions inertes permettent de caractériser l’importance des interactions choc/turbulence avec une attention particulière accordée à la description des fluctuations de composition à l’échelle non-résolue (i.e. sous-maille). Compte tenu de leur niveau de résolution,les simulations réactives permettent quant à elles une analyse détaillée du mode de stabilisation et des régimes de combustion turbulente rencontrés fournissant ainsi des informations très précieuses quant à l’adéquation des modélisations existantes pour ces conditions extrêmes.
This dissertation is devoted to the Large-eddy simulation (LES) study of a wall hydrogen underexpanded jet in a supersonic crossflow of vitiated air. This configuration is representative of flow conditions encountered in aerospace engines such as supersonic combustion ramjet (scramjets). Indeed, future of high-speed transport systems heavily depends on the development of this type of engine. Under such conditions, the high temperature flow of vitiated air is maintained supersonic in the combustion chamber to reduce effects of heating and dissociation. The mixing and combustion processes that develop downstream of the fuel jet are studied. This work is based on the use of a high fidelity numerical simulation: CREAMS (Compressible REActive Multi-species Solver) which is developed at the Pprime Institute. This computational solver makes use of high precision numerical schemes: a 3rd order Runge–Kutta scheme for the time integration combines with a 7th order WENO and 8th order centered scheme for the spatial discretisation. Non-reactive simulations allow to characterize the importance of shock/turbulence interactions with special attention paid to the description of the unresolved (i.e. sub-grid scale) scalar fluctuations. The reactive simulations allow to perform a detailed analysis of the stabilization…
Advisors/Committee Members: Mura, Arnaud (thesis director), Lehnasch, Guillaume (thesis director).
Subjects/Keywords: Auto-allumage; Auto-ignition
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APA (6th Edition):
Techer, A. (2017). Simulation aux grandes échelles implicite et explicite de la combustion supersonique : Implicit and Explicit Large-Eddy Simulation of Supersonic Combustion. (Doctoral Dissertation). Chasseneuil-du-Poitou, Ecole nationale supérieure de mécanique et d'aérotechnique. Retrieved from http://www.theses.fr/2017ESMA0020
Chicago Manual of Style (16th Edition):
Techer, Anthony. “Simulation aux grandes échelles implicite et explicite de la combustion supersonique : Implicit and Explicit Large-Eddy Simulation of Supersonic Combustion.” 2017. Doctoral Dissertation, Chasseneuil-du-Poitou, Ecole nationale supérieure de mécanique et d'aérotechnique. Accessed April 18, 2021.
http://www.theses.fr/2017ESMA0020.
MLA Handbook (7th Edition):
Techer, Anthony. “Simulation aux grandes échelles implicite et explicite de la combustion supersonique : Implicit and Explicit Large-Eddy Simulation of Supersonic Combustion.” 2017. Web. 18 Apr 2021.
Vancouver:
Techer A. Simulation aux grandes échelles implicite et explicite de la combustion supersonique : Implicit and Explicit Large-Eddy Simulation of Supersonic Combustion. [Internet] [Doctoral dissertation]. Chasseneuil-du-Poitou, Ecole nationale supérieure de mécanique et d'aérotechnique; 2017. [cited 2021 Apr 18].
Available from: http://www.theses.fr/2017ESMA0020.
Council of Science Editors:
Techer A. Simulation aux grandes échelles implicite et explicite de la combustion supersonique : Implicit and Explicit Large-Eddy Simulation of Supersonic Combustion. [Doctoral Dissertation]. Chasseneuil-du-Poitou, Ecole nationale supérieure de mécanique et d'aérotechnique; 2017. Available from: http://www.theses.fr/2017ESMA0020
University of Rochester
13.
Nora, Ryan (1986 - ).
Hydrodynamics of inertial confinement fusion:
conventional hot spot and shock ignition.
Degree: PhD, 2015, University of Rochester
URL: http://hdl.handle.net/1802/29713
► The hydrodynamics of inertial confinement fusion (ICF) implosions, both conventional hot spot and shock ignition (SI), are discussed. A one-dimensional planar compressible–piston-like model is used…
(more)
▼ The hydrodynamics of inertial confinement fusion
(ICF) implosions, both conventional hot spot and shock ignition
(SI), are discussed. A one-dimensional planar
compressible–piston-like model is used to investigate the basic
physics behind conventional hot spot and shock-ignition implosions.
Three ignitor shock techniques are found to mitigate the effects of
rarefaction waves, enhance the stagnation hot-spot pressure, and
improve the ignition conditions. These techniques are compared and
the optimal energy ratio between the initial shell kinetic energy
and the ignitor pulse energy is determined. We demonstrated for the
first time the ability to launch shocks of several-hundred Mbars in
spherical targets at SI relevant laser intensities, a milestone for
SI. The temporal delay between the launching of the strong shock at
the outer surface of the spherical target and the shock converges
at the center is used to infer the ablation
and shock pressures.
Peak ablation pressures exceeding 300 Mbar are inferred at absorbed
laser intensities of ~3 x 1015
W/cm2. The theory of ignition for ICF
capsules
is used to determine hydrodynamically-equivalent ignition
performance requirements on OMEGA. A reasonable combination of
neutron yield and areal density for OMEGA hydro-equivalent ignition
is ~6 x 1013 and 0.3
g/cm2, respectively.
Subjects/Keywords: Inertial confinement fusion; Shock ignition
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APA (6th Edition):
Nora, R. (. -. ). (2015). Hydrodynamics of inertial confinement fusion:
conventional hot spot and shock ignition. (Doctoral Dissertation). University of Rochester. Retrieved from http://hdl.handle.net/1802/29713
Chicago Manual of Style (16th Edition):
Nora, Ryan (1986 - ). “Hydrodynamics of inertial confinement fusion:
conventional hot spot and shock ignition.” 2015. Doctoral Dissertation, University of Rochester. Accessed April 18, 2021.
http://hdl.handle.net/1802/29713.
MLA Handbook (7th Edition):
Nora, Ryan (1986 - ). “Hydrodynamics of inertial confinement fusion:
conventional hot spot and shock ignition.” 2015. Web. 18 Apr 2021.
Vancouver:
Nora R(-). Hydrodynamics of inertial confinement fusion:
conventional hot spot and shock ignition. [Internet] [Doctoral dissertation]. University of Rochester; 2015. [cited 2021 Apr 18].
Available from: http://hdl.handle.net/1802/29713.
Council of Science Editors:
Nora R(-). Hydrodynamics of inertial confinement fusion:
conventional hot spot and shock ignition. [Doctoral Dissertation]. University of Rochester; 2015. Available from: http://hdl.handle.net/1802/29713
Oregon State University
14.
Okhovat, Sebastian.
Temperature Evolution of Spark Kernels in Quiescent and Cross-flow Conditions.
Degree: MS, Mechanical Engineering, 2015, Oregon State University
URL: http://hdl.handle.net/1957/57994
► Numerous physical and chemical processes are required for successful ignition of a flammable mixture, many of which have been well characterized. However, one aspect of…
(more)
▼ Numerous physical and chemical processes are required for successful
ignition of a flammable mixture, many of which have been well characterized. However, one aspect of the
ignition process that has received limited consideration is understanding the temperature of the spark kernel. A spark kernel is the volume of heated gas that develops after plasma formation and dissipation by an electrical discharge. Thermal measurements are critical for determining if reactions become self-sustaining and improving the validity of modeling efforts. The need for quantified kernel temperatures is extended to conditions that approach the flow fields within combustion applications, such as gas turbine engines. Based on the motivation, the focus of this work was to determine the temperature of kernels and investigate the influence a cross-flow has on the temporal temperature evolution. Representative results were compared against kernel temperatures in a quiescent environment to highlight differences between the two flow conditions. In this study, a sunken fire igniter was placed in an open loop wind tunnel and discharged into a non-reacting cross-flow. Kernel temperatures, after the plasma dissipated, were determined from radiation intensity measurements and by solving the radiation transfer equation. The temperature evolution was investigated in a quiescent environment and for a range of cross-flow velocities (5.8-15.6 m/s). For both quiescent and cross-flow conditions, kernels developed into a toroidal vortex. Surrounding air was entrained into the center of the kernel, resulting in relatively lower temperatures compared to the edges. Average peak kernel temperatures in quiescent conditions were 950 K, whereas kernels in a cross-flow approached 1250 K. The higher peak temperatures were attributed to a reduced relative velocity of the vortex caused by the interaction with the cross-flow. This resulted in decreased entrainment, particularly located at the upstream side of the kernel. Most of the temperature evolution of kernels was experienced within 1.3 ms after plasma was no longer detected; up to a 500 K difference was determined between 0.6 and 1.3 ms. Kernels beyond 1.3 ms reached a uniform temperature near 600 K and had little to no variation as radiation intensities dissipated beyond optical detection. Bifurcation of kernels was detected in one-third of all spark events for both quiescent and cross-flow conditions. The sensible energy of kernels was reported to decrease with time for all cases. Higher cross-flow velocities resulted in less sensible energy. This was attributed to a reduction in apparent kernel volume even with higher temperatures.
Advisors/Committee Members: Blunck, David (advisor), Squires, Nancy (committee member).
Subjects/Keywords: cross-flow; Spark ignition engines
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APA ·
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APA (6th Edition):
Okhovat, S. (2015). Temperature Evolution of Spark Kernels in Quiescent and Cross-flow Conditions. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/57994
Chicago Manual of Style (16th Edition):
Okhovat, Sebastian. “Temperature Evolution of Spark Kernels in Quiescent and Cross-flow Conditions.” 2015. Masters Thesis, Oregon State University. Accessed April 18, 2021.
http://hdl.handle.net/1957/57994.
MLA Handbook (7th Edition):
Okhovat, Sebastian. “Temperature Evolution of Spark Kernels in Quiescent and Cross-flow Conditions.” 2015. Web. 18 Apr 2021.
Vancouver:
Okhovat S. Temperature Evolution of Spark Kernels in Quiescent and Cross-flow Conditions. [Internet] [Masters thesis]. Oregon State University; 2015. [cited 2021 Apr 18].
Available from: http://hdl.handle.net/1957/57994.
Council of Science Editors:
Okhovat S. Temperature Evolution of Spark Kernels in Quiescent and Cross-flow Conditions. [Masters Thesis]. Oregon State University; 2015. Available from: http://hdl.handle.net/1957/57994
University of Colorado
15.
Cameron, Drew Morales.
Autoignition Studies of Gasoline Surrogate Fuels in the Advanced Fuel Ignition Delay Analyzer.
Degree: MS, Mechanical Engineering, 2017, University of Colorado
URL: https://scholar.colorado.edu/mcen_gradetds/150
► Improving vehicle efficiency is a substantial way to reduce CO2 emissions from the transportation sector. The most limiting factor of spark ignition (SI) gasoline engine…
(more)
▼ Improving vehicle efficiency is a substantial way to reduce CO
2 emissions from the transportation sector. The most limiting factor of spark
ignition (SI) gasoline engine efficiency is the phenomenon known as knocking. The current methods to characterize fuel knock resistance are with the Research Octane Number (RON) and Motor Octane Number (MON) methods. However, it has been shown that these engine-based test methods do not directly predict knock resistance in modern direct injection (DI) gasoline engines, especially under boosted conditions. Alternative test devices have been used to more directly study
ignition kinetics. Constant volume combustion chambers (CVCCs) have been used to obtain valuable autoignition data at a broader ranger of pressure and temperature conditions than the single point engine operating conditions of the RON and MON tests. This study uses a new CVCC to study gasoline range fuels at engine relevant conditions to collect autoignition data on a set of simple gasoline surrogate fuels and correlate these data to the fuel chemistry and properties. A set of nine gasoline surrogates, with and without oxygenates were tested in the Advanced Fuel
Ignition Delay Analyzer (AFIDA). The main outputs of this study are 3D surfaces of autoignition (
ignition delay time) as a function of pressure and temperature. These data more completely characterize
ignition delay at a wide range of engine relevant conditions, providing more insight than the RON and MON tests. Linear regression was performed between the
ignition delay time and the fuel composition and properties, however significant correlations were not found. This study paves the way for more complex, full-boiling range gasoline fuels to be characterized in the AFIDA, fuels which are too complex to model with chemical kinetics.
Advisors/Committee Members: John W. Daily, Peter Hamlington, Nicole Labbe.
Subjects/Keywords: auto-ignition; combustion; fuel; gasoline surrogate; ignition kinetics; spark ignition engine; Advanced Fuel Ignition Delay Analyzer (AFIDA); Chemistry; Mechanical Engineering
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APA (6th Edition):
Cameron, D. M. (2017). Autoignition Studies of Gasoline Surrogate Fuels in the Advanced Fuel Ignition Delay Analyzer. (Masters Thesis). University of Colorado. Retrieved from https://scholar.colorado.edu/mcen_gradetds/150
Chicago Manual of Style (16th Edition):
Cameron, Drew Morales. “Autoignition Studies of Gasoline Surrogate Fuels in the Advanced Fuel Ignition Delay Analyzer.” 2017. Masters Thesis, University of Colorado. Accessed April 18, 2021.
https://scholar.colorado.edu/mcen_gradetds/150.
MLA Handbook (7th Edition):
Cameron, Drew Morales. “Autoignition Studies of Gasoline Surrogate Fuels in the Advanced Fuel Ignition Delay Analyzer.” 2017. Web. 18 Apr 2021.
Vancouver:
Cameron DM. Autoignition Studies of Gasoline Surrogate Fuels in the Advanced Fuel Ignition Delay Analyzer. [Internet] [Masters thesis]. University of Colorado; 2017. [cited 2021 Apr 18].
Available from: https://scholar.colorado.edu/mcen_gradetds/150.
Council of Science Editors:
Cameron DM. Autoignition Studies of Gasoline Surrogate Fuels in the Advanced Fuel Ignition Delay Analyzer. [Masters Thesis]. University of Colorado; 2017. Available from: https://scholar.colorado.edu/mcen_gradetds/150
Michigan Technological University
16.
Chen, Wei.
Impact of Spark Ignition Duration, Energy and Phasing on Combustion and Performance in a Gasoline Turbocharged Direct Injection Engine near the Dilute Limit.
Degree: PhD, Department of Mechanical Engineering-Engineering Mechanics, 2015, Michigan Technological University
URL: https://digitalcommons.mtu.edu/etdr/11
► High dilution combustion is a promising technology to continue improving gasoline spark-ignition (SI) engine fuel conversion efficiency and for the reduction of nitrogen oxide…
(more)
▼ High dilution combustion is a promising technology to continue improving gasoline spark-
ignition (SI) engine fuel conversion efficiency and for the reduction of nitrogen oxide emissions. Dilution is principally limited in SI engines by
ignition, flame kernel development, successful transition to the turbulent propagating flame during the bulk burn portion of combustion process and the resulting combustion stability. However, the SI gasoline turbocharged directed injection (GTDI) engine
ignition requirements, especially at the combustion stability limit, are not well understood and must be better characterized to enable improved designs.
A multi-discharge, electronically control, inductive
ignition system was employed on a multi-cylinder GTDI engine to control and quantify the
ignition and combustion processes under high dilution operation. The
ignition system, developed by Ford Motor Company and integrated on the engine, is a Variable Output
Ignition System (VOIS) enabling flexible spark discharge patterns with control of
ignition energy, duration, and phasing. In this study two coil discharges were examined under both continuous and discontinuous settings by delaying the second discharge with respect to the first.
Ignition secondary voltage and current were measured with a high speed analog to digital recorder to measure and quantify the breakdown voltages,
ignition duration,
ignition energy, and other
ignition metrics over 300 cycles of continuous engine operation. Simultaneously 300 cycles of crank-angle resolved cylinder pressure and other data was recorded to analyze cycle based work and combustion rates and to correlate
ignition with combustion.
With respect to
ignition analysis and correlations, the results show that the breakdown voltage of the second discharge was correlated to the second coil discharge timing. The second breakdown voltage increased when the second coil discharge timing was retarded. It was also found that the glow energy was highly correlated to the
ignition duration on a cycle-by-cycle basis. The
ignition duration decreases with higher
ignition voltages during glow discharge giving higher total glow energy as a result of hypothesized arc stretching.
With respect to
ignition and combustion correlations, the flame kernel development period was found to be weakly correlated to both the
ignition duration and energy. The breakdown and arc energy of the second discharge had higher correlation to the combustion phasing than the glow energy of the second discharge.
With respect to engine performance in a dual-coil multi-discharge
ignition, an optimal
ignition energy phase delay time exists with a fixed total
ignition energy. A delayed second coil discharge at the dilution limit can convert abnormal combustion cycles to normal burn cycles. The combustion phasing of these converted cycles is dependent on the phasing of the second discharge. The results also showed that combustion phasing was strongly correlated to the flame kernel development period. The gross…
Advisors/Committee Members: Jeffery D. Naber, Bo Chen.
Subjects/Keywords: Dual-coil Ignition System; EGR Limit; Direct Injection Spark Ignition Engine; Combustion Stability; Ignition Energy; Ignition Duration; Automotive Engineering
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APA (6th Edition):
Chen, W. (2015). Impact of Spark Ignition Duration, Energy and Phasing on Combustion and Performance in a Gasoline Turbocharged Direct Injection Engine near the Dilute Limit. (Doctoral Dissertation). Michigan Technological University. Retrieved from https://digitalcommons.mtu.edu/etdr/11
Chicago Manual of Style (16th Edition):
Chen, Wei. “Impact of Spark Ignition Duration, Energy and Phasing on Combustion and Performance in a Gasoline Turbocharged Direct Injection Engine near the Dilute Limit.” 2015. Doctoral Dissertation, Michigan Technological University. Accessed April 18, 2021.
https://digitalcommons.mtu.edu/etdr/11.
MLA Handbook (7th Edition):
Chen, Wei. “Impact of Spark Ignition Duration, Energy and Phasing on Combustion and Performance in a Gasoline Turbocharged Direct Injection Engine near the Dilute Limit.” 2015. Web. 18 Apr 2021.
Vancouver:
Chen W. Impact of Spark Ignition Duration, Energy and Phasing on Combustion and Performance in a Gasoline Turbocharged Direct Injection Engine near the Dilute Limit. [Internet] [Doctoral dissertation]. Michigan Technological University; 2015. [cited 2021 Apr 18].
Available from: https://digitalcommons.mtu.edu/etdr/11.
Council of Science Editors:
Chen W. Impact of Spark Ignition Duration, Energy and Phasing on Combustion and Performance in a Gasoline Turbocharged Direct Injection Engine near the Dilute Limit. [Doctoral Dissertation]. Michigan Technological University; 2015. Available from: https://digitalcommons.mtu.edu/etdr/11
University of Illinois – Urbana-Champaign
17.
Chan, Chee Haw.
Ignition limits of explosively dispersed fuel.
Degree: MS, Mechanical Engineering, 2016, University of Illinois – Urbana-Champaign
URL: http://hdl.handle.net/2142/92720
► This thesis aims to explore the ignition limits of explosively dispersed fuel. Significant damage can result from the explosive dispersal and ignition of kerosene in…
(more)
▼ This thesis aims to explore the
ignition limits of explosively dispersed fuel. Significant damage can result from the explosive dispersal and
ignition of kerosene in the event of an attack on or an accident in a military facility or vessel carrying kerosene fuel tanks. As such, the work conducted approaches the
ignition of explosively dispersed fuel from the context of safety in the hopes of either minimizing the amount of fuel ignited or completely eliminating fuel burn.
A test article was designed to explosively disperse and ignite kerosene fuel, using flash powder as the driving charge. These test articles were ignited in a blast chamber located at the University of Illinois at Urbana-Champaign, and the chamber pressure was recorded to determine the energy released. Some high-speed imaging was also conducted at a different facility on campus. The charge-to-fuel mass ratio was varied, while holding the fuel mass constant, to determine a relationship between the mass ratio and fuel burn fraction. A primary motivation of this study is to find a critical mass ratio at which the fuel does not burn
It was observed that kerosene is sensitive to
ignition when explosively dispersed in the test configuration. This sensitivity is suspected to result from local heating of rich regions of the fuel cloud by dispersed chunks of burning flash powder. No mass ratio was found at which fuel did not burn after being explosively dispersed. However, a different critical mass ratio was observed which marked the upper limit of fuel burn fraction. This limit was determined to be 63% fuel burn.
Advisors/Committee Members: Glumac, Nick (advisor).
Subjects/Keywords: Ignition; Explosion; Fuel; Kerosene
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APA (6th Edition):
Chan, C. H. (2016). Ignition limits of explosively dispersed fuel. (Thesis). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/92720
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Chan, Chee Haw. “Ignition limits of explosively dispersed fuel.” 2016. Thesis, University of Illinois – Urbana-Champaign. Accessed April 18, 2021.
http://hdl.handle.net/2142/92720.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Chan, Chee Haw. “Ignition limits of explosively dispersed fuel.” 2016. Web. 18 Apr 2021.
Vancouver:
Chan CH. Ignition limits of explosively dispersed fuel. [Internet] [Thesis]. University of Illinois – Urbana-Champaign; 2016. [cited 2021 Apr 18].
Available from: http://hdl.handle.net/2142/92720.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Chan CH. Ignition limits of explosively dispersed fuel. [Thesis]. University of Illinois – Urbana-Champaign; 2016. Available from: http://hdl.handle.net/2142/92720
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
18.
Royle, Ryan.
Effects of Laser Frequency and Multiple Beams on Hot Electron Generation in Fast Ignition.
Degree: 2012, University of Nevada – Reno
URL: http://hdl.handle.net/11714/3688
► Inertial confinement fusion (ICF) is one approach to harnessing fusion power for the purpose of energy production in which a small deuterium-tritium capsule is imploded…
(more)
▼ Inertial confinement fusion (ICF) is one approach to harnessing fusion power for the purpose of energy production in which a small deuterium-tritium capsule is imploded to about a thousand times solid density with ultra-intense lasers. In the fast
ignition (FI) scheme, a picosecond petawatt laser pulse is used to deposit ∼10 kJ of energy in ∼10 ps into a small hot-spot at the periphery of the compressed core, igniting a fusion burn wave. FI promises a much higher energy gain over the conventional central hot-spot
ignition scheme in which
ignition is achieved through compression alone. Sufficient energy coupling between
ignition laser and implosion core is critical for the feasibility of the FI scheme. Laser-core energy coupling is mediated by hot electrons which absorb laser energy near the critical density and propagate to the dense core, depositing their energy primarily through collisions. The hot electron energy distribution plays a large role in achieving efficient energy coupling since electrons with energy much greater than a few MeV will only deposit a small fraction of their energy into the hot-spot region due to reduced collisional cross section. It is understood that it may be necessary to use the second or third harmonic of the 1.05 μm Nd glass laser to reduce the average hot electron energy closer to the few-MeV range. Also, it is likely that multiple
ignition beams will be used to achieve the required intensities. In this study, 2D particle-in-cell simulations are used to examine the effects of frequency doubling and tripling of a 1 μm laser as well as effects of using various dual-beam configurations. While the hot-electron energy spectrum is indeed shifted closer to the few-MeV range for higher frequency beams, the overall energy absorption is reduced, canceling the gain from higher efficiency. For a fixed total laser input energy, we find that the amount of hot electron energy able to be deposited into the core hot-spot is fairly insensitive to the laser configuration used. Our results hint that the more important issue at hand may be divergence and transport of the hot electrons, which tend to spray into 2π radians due to instabilities and current filamentation present in the laser-plasma interaction region.
Advisors/Committee Members: Sentoku, Yasuhiko (advisor), Ivanov, Vladimir (committee member), Harris, Frederick (committee member).
Subjects/Keywords: fast ignition; particle-in-cell
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APA (6th Edition):
Royle, R. (2012). Effects of Laser Frequency and Multiple Beams on Hot Electron Generation in Fast Ignition. (Thesis). University of Nevada – Reno. Retrieved from http://hdl.handle.net/11714/3688
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Royle, Ryan. “Effects of Laser Frequency and Multiple Beams on Hot Electron Generation in Fast Ignition.” 2012. Thesis, University of Nevada – Reno. Accessed April 18, 2021.
http://hdl.handle.net/11714/3688.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Royle, Ryan. “Effects of Laser Frequency and Multiple Beams on Hot Electron Generation in Fast Ignition.” 2012. Web. 18 Apr 2021.
Vancouver:
Royle R. Effects of Laser Frequency and Multiple Beams on Hot Electron Generation in Fast Ignition. [Internet] [Thesis]. University of Nevada – Reno; 2012. [cited 2021 Apr 18].
Available from: http://hdl.handle.net/11714/3688.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Royle R. Effects of Laser Frequency and Multiple Beams on Hot Electron Generation in Fast Ignition. [Thesis]. University of Nevada – Reno; 2012. Available from: http://hdl.handle.net/11714/3688
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Colorado State University
19.
Wilvert, Hurley Nicholas.
Development and testing of a solid core fiber optic delivery system and ultraviolet preionization for laser ignition.
Degree: MS(M.S.), Mechanical Engineering, 2012, Colorado State University
URL: http://hdl.handle.net/10217/68142
► Laser ignition of natural gas engines has shown potential to improve many facets of engine performance including brake thermal efficiency, exhaust emissions, and durability as…
(more)
▼ Laser
ignition of natural gas engines has shown potential to improve many facets of engine performance including brake thermal efficiency, exhaust emissions, and durability as compared with traditional spark
ignition. Laser
ignition technology has yet to transition to industry primarily because no system for reliably and safely delivering the laser pulse to the combustion chamber exists. This thesis presents a novel fiber optic delivery approach using solid core multimode step index silica fibers with large cladding diameters (400 μm core, 720 μm cladding). Testing was done on the fibers to determine their response to bending, vibration, high power input, and long duration beam transmission. It was found that in configurations representative of what is required on a real engine, and in the presence of vibration, reliable spark formation could be achieved in pressures as low as 3.4 bar using a specially designed optical spark plug. Comparative tests between the fiber delivered laser
ignition system and a traditional J-gap spark plug were performed on a single cylinder Waukesha Cooperative Fuel Research (CFR) engine running on bottled methane. Tests were run at three different Net Mean Effective Pressures (NMEP) of 6, 8, and 12 bar at various air-fuel ratios. Results indicate reliable performance of the fiber and improved engine performance at high NMEP and lean conditions. Thesis research also includes initial studies into the use of dual laser pulses for plasma formation and
ignition. In this approach, a first ultraviolet pulse preionizes a volume of air while a second overlapped pulse adds additional energy. Electron density measurements reveal the ultraviolet beam generates substantial preionization even with no visual breakdown, and Schlieren images are used to study the interaction between the two beams at atmospheric and lower pressures.
Advisors/Committee Members: Yalin, Azer (advisor), Marchese, Anthony (committee member), Rocca, Jorge (committee member).
Subjects/Keywords: fiber optic; laser ignition
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Manager
APA (6th Edition):
Wilvert, H. N. (2012). Development and testing of a solid core fiber optic delivery system and ultraviolet preionization for laser ignition. (Masters Thesis). Colorado State University. Retrieved from http://hdl.handle.net/10217/68142
Chicago Manual of Style (16th Edition):
Wilvert, Hurley Nicholas. “Development and testing of a solid core fiber optic delivery system and ultraviolet preionization for laser ignition.” 2012. Masters Thesis, Colorado State University. Accessed April 18, 2021.
http://hdl.handle.net/10217/68142.
MLA Handbook (7th Edition):
Wilvert, Hurley Nicholas. “Development and testing of a solid core fiber optic delivery system and ultraviolet preionization for laser ignition.” 2012. Web. 18 Apr 2021.
Vancouver:
Wilvert HN. Development and testing of a solid core fiber optic delivery system and ultraviolet preionization for laser ignition. [Internet] [Masters thesis]. Colorado State University; 2012. [cited 2021 Apr 18].
Available from: http://hdl.handle.net/10217/68142.
Council of Science Editors:
Wilvert HN. Development and testing of a solid core fiber optic delivery system and ultraviolet preionization for laser ignition. [Masters Thesis]. Colorado State University; 2012. Available from: http://hdl.handle.net/10217/68142
20.
Rose, Evan Noah.
Autoignition Dynamics and Combustion of n-Dodecane
Dropletsunder Transcritical Conditions.
Degree: MSs, EMC - Mechanical Engineering, 2019, Case Western Reserve University School of Graduate Studies
URL: http://rave.ohiolink.edu/etdc/view?acc_num=case1554288408975334
► Understanding the spontaneous ignition and burning behavior of liquid fuels is criticalto improving the performance of modern combustion devices. This work examinesthe effects of varying…
(more)
▼ Understanding the spontaneous
ignition and burning
behavior of liquid fuels is criticalto improving the performance of
modern combustion devices. This work examinesthe effects of varying
ambient temperature and pressure on the autoignition and
burningcharacteristics of fiber-supported n-dodecane fuel droplets
in normal gravity and inmicrogravity. Ambient temperatures and
pressures were 500 to 1000 K and 1 to 25 atm,respectively,
encompassing the transcritical region for n-dodecane. The results
show thedynamics of
ignition with the formation of a cool-flame
front and a hot-flame front priorto the final establishment of a
diffusion flame surrounding the droplet. These phenomenaare
observed for both normal gravity and microgravity environments.
Measurementof two-stage
ignition delay times shows qualitative
agreement with previous research.
Advisors/Committee Members: Nayagam, Vedha (Advisor).
Subjects/Keywords: Mechanical Engineering; combustion; autoignition; ignition; droplet; NTC; two-stage ignition; dodecane
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APA (6th Edition):
Rose, E. N. (2019). Autoignition Dynamics and Combustion of n-Dodecane
Dropletsunder Transcritical Conditions. (Masters Thesis). Case Western Reserve University School of Graduate Studies. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=case1554288408975334
Chicago Manual of Style (16th Edition):
Rose, Evan Noah. “Autoignition Dynamics and Combustion of n-Dodecane
Dropletsunder Transcritical Conditions.” 2019. Masters Thesis, Case Western Reserve University School of Graduate Studies. Accessed April 18, 2021.
http://rave.ohiolink.edu/etdc/view?acc_num=case1554288408975334.
MLA Handbook (7th Edition):
Rose, Evan Noah. “Autoignition Dynamics and Combustion of n-Dodecane
Dropletsunder Transcritical Conditions.” 2019. Web. 18 Apr 2021.
Vancouver:
Rose EN. Autoignition Dynamics and Combustion of n-Dodecane
Dropletsunder Transcritical Conditions. [Internet] [Masters thesis]. Case Western Reserve University School of Graduate Studies; 2019. [cited 2021 Apr 18].
Available from: http://rave.ohiolink.edu/etdc/view?acc_num=case1554288408975334.
Council of Science Editors:
Rose EN. Autoignition Dynamics and Combustion of n-Dodecane
Dropletsunder Transcritical Conditions. [Masters Thesis]. Case Western Reserve University School of Graduate Studies; 2019. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=case1554288408975334
Brno University of Technology
21.
Drahoš, Dominik.
Mikrokontrolérem řízené zapalování: Ignition system control by microcontroler.
Degree: 2019, Brno University of Technology
URL: http://hdl.handle.net/11012/60461
► This thesis describes the design of ignition system controlled by microcontroller. In the introduction, we are familiar with the principle of ignition combustion engines. It…
(more)
▼ This thesis describes the design of
ignition system controlled by microcontroller. In the introduction, we are familiar with the principle of
ignition combustion engines. It also contains a list of existing types
ignition. Finally portrays the entire design process circuitry electronic
ignition and software solution.
Advisors/Committee Members: Macho, Tomáš (advisor), Petyovský, Petr (referee).
Subjects/Keywords: Elektronické zapalování; tranzistorové zapalování; řízení předstihu; návrh zapalování; Electronic ignition; transistor ignition; timing control; ignition proposal
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APA (6th Edition):
Drahoš, D. (2019). Mikrokontrolérem řízené zapalování: Ignition system control by microcontroler. (Thesis). Brno University of Technology. Retrieved from http://hdl.handle.net/11012/60461
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Drahoš, Dominik. “Mikrokontrolérem řízené zapalování: Ignition system control by microcontroler.” 2019. Thesis, Brno University of Technology. Accessed April 18, 2021.
http://hdl.handle.net/11012/60461.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Drahoš, Dominik. “Mikrokontrolérem řízené zapalování: Ignition system control by microcontroler.” 2019. Web. 18 Apr 2021.
Vancouver:
Drahoš D. Mikrokontrolérem řízené zapalování: Ignition system control by microcontroler. [Internet] [Thesis]. Brno University of Technology; 2019. [cited 2021 Apr 18].
Available from: http://hdl.handle.net/11012/60461.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Drahoš D. Mikrokontrolérem řízené zapalování: Ignition system control by microcontroler. [Thesis]. Brno University of Technology; 2019. Available from: http://hdl.handle.net/11012/60461
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Brunel University
22.
Bureshaid, Khalifa.
A study of turbulent jet ignition combustion in an optical research engine with alternative fuels.
Degree: PhD, 2019, Brunel University
URL: http://bura.brunel.ac.uk/handle/2438/20076
;
https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.814396
► Turbulent Jet Ignition (TJI) is an advanced ignition process where ultra-lean mixtures can ignite in standard gasoline spark ignition engine. In this research, a TJI…
(more)
▼ Turbulent Jet Ignition (TJI) is an advanced ignition process where ultra-lean mixtures can ignite in standard gasoline spark ignition engine. In this research, a TJI unit by Mahle Powertrain USA was adopted and studied in a bespoke single-cylinder engine with optical acess. The TJI device features a very small pre-chamber that is connected to the main chamber by multiple small orifices and can be separately fuelled by a direct fuel injector. The spark plug shifts from the main chamber to the pre-chamber to ignite the pre-chamber mixture. A new cylinder head was designed and manufactured to accommodate the TJI unit and optical windows on the top and sides of the cylinder head block. A new direct inejector (DI) fuel supply system was set up for direct fuel injection in the pre-chamber. A new engine control and a data system were commissioned and used for engine experiments and heat release analysis. High-speed combustion imaging and spectroscopic techniques were developed to study the ignition and combustion in the main chamber through high-speed cameras and spectrographic equipment. Thermodynamic studies on TJI combustion in a single-cylinder engine demonstrate the ability of TJI to extend the lean-burn limit of gasoline operation at different engine speeds and loads. Similar effects are also observed with engine operations fuelled with ethanol and wet-ethanol. TJI exerts the greatest effect in extending the lean-burn limit of ethanol fuel and leads to near-zero NOx emissions near the lean-burn limit. In addition, the TJI ethanol engine operation has higher thermal efficiency as well as lower HC and CO emissions than the gasoline operation. Spectroscopic results reveal that ethanol combustion produces higher chemiluminescent emissions than gasoline during the normal spark ignition combustion in the main chamber. The OH spectral peak at 310 nm is the highest throughout the ignition and combustion, followed by CH emission at 430 nm and HCO at 330 nm. Their intensities peak before the maximum heat release rates measured by the in-cylinder pressure. Emission spectra produced by the pre-chamber ignition are stronger than the normal spark ignition in the main chamber. The highest emission intensities are observed with the fuelled pre-chamber ignition even with leaner air–fuel mixture in the main chamber. As pre-chamber fuel is increased, the pre-chamber pressure rises faster to a higher peak value, producing greater pressure differential between the pre-chamber and main chamber and faster turbulent jets of partially burned products at higher temperature. The increase in the pre-chamber pressure causes the jets to travel deeper into the main chamber and enlarges the ignition sites. In addition, the ignition delay of the main chamber combustion is shortened due to the higher temperature of turbulent jets, as indicated by the stonger emission spectra. The turbulent ignition jets of ethanol are characterised with greater momentum than gasoline due to the faster combustion speed of ethanol and higher energy input. When the…
Subjects/Keywords: Mahle Jet Ignition (MJI); Spark Ignition (SI); Stratified change engine; Lean burning; The hydrogen-assisted jet ignition (HAJI)
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APA (6th Edition):
Bureshaid, K. (2019). A study of turbulent jet ignition combustion in an optical research engine with alternative fuels. (Doctoral Dissertation). Brunel University. Retrieved from http://bura.brunel.ac.uk/handle/2438/20076 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.814396
Chicago Manual of Style (16th Edition):
Bureshaid, Khalifa. “A study of turbulent jet ignition combustion in an optical research engine with alternative fuels.” 2019. Doctoral Dissertation, Brunel University. Accessed April 18, 2021.
http://bura.brunel.ac.uk/handle/2438/20076 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.814396.
MLA Handbook (7th Edition):
Bureshaid, Khalifa. “A study of turbulent jet ignition combustion in an optical research engine with alternative fuels.” 2019. Web. 18 Apr 2021.
Vancouver:
Bureshaid K. A study of turbulent jet ignition combustion in an optical research engine with alternative fuels. [Internet] [Doctoral dissertation]. Brunel University; 2019. [cited 2021 Apr 18].
Available from: http://bura.brunel.ac.uk/handle/2438/20076 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.814396.
Council of Science Editors:
Bureshaid K. A study of turbulent jet ignition combustion in an optical research engine with alternative fuels. [Doctoral Dissertation]. Brunel University; 2019. Available from: http://bura.brunel.ac.uk/handle/2438/20076 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.814396
NSYSU
23.
Zeng, Jian-Jhang.
Investigation on Single-Pulse Ignition for Metal Halide Lamps.
Degree: Master, Electrical Engineering, 2010, NSYSU
URL: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0907110-181635
► Conventionally, metal halide lamps were ignited by striking the lamp electrodes several times with high voltage pulses. Such a starting scenario causes uncomfortable light strobes…
(more)
▼ Conventionally, metal halide lamps were ignited by striking the lamp electrodes several times with high voltage pulses. Such a starting scenario causes uncomfortable light strobes to users. To solve this problem, this thesis attempts to ignite small-wattage metal halide lamps with a single pulse strike. At first, the forms of the high voltage pulses required for breaking down the electrodes are investigated. After being broken down, a continuous current is critical for sustaining the lamp arc. With conventional electronic ballasts, however, the lamp current tends to resonate to zero resulting in break of the lamp arc. This problem can be solved by adding an extra switch to remove the capacitor of the output filter during the
ignition stage. An electronic ballast is designed and tested on 70 W metal halide lamps with an associated switch for single pulse striking. Experiments have demonstrated that the proposed
ignition criteria can start up the lamps successfully with a single-pulse high voltage.
Advisors/Committee Members: Jia-You Lee (chair), Chin-Sien Moo (committee member), Tsai-Fu Lin (chair), Tsorng-Juu Liang (chair), Kuei-Hsiang Chao (chair).
Subjects/Keywords: ignition; Metal halide lamp (MHL); electronic ballats
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CSE |
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APA (6th Edition):
Zeng, J. (2010). Investigation on Single-Pulse Ignition for Metal Halide Lamps. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0907110-181635
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Zeng, Jian-Jhang. “Investigation on Single-Pulse Ignition for Metal Halide Lamps.” 2010. Thesis, NSYSU. Accessed April 18, 2021.
http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0907110-181635.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Zeng, Jian-Jhang. “Investigation on Single-Pulse Ignition for Metal Halide Lamps.” 2010. Web. 18 Apr 2021.
Vancouver:
Zeng J. Investigation on Single-Pulse Ignition for Metal Halide Lamps. [Internet] [Thesis]. NSYSU; 2010. [cited 2021 Apr 18].
Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0907110-181635.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Zeng J. Investigation on Single-Pulse Ignition for Metal Halide Lamps. [Thesis]. NSYSU; 2010. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0907110-181635
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Mississippi State University
24.
Polk, Andrew C.
Detailed characterization of conventional and low temperature dual fuel combustion in compression ignition engines.
Degree: PhD, Mechanical Engineering, 2013, Mississippi State University
URL: http://sun.library.msstate.edu/ETD-db/theses/available/etd-04012013-092845/
;
► The goal of this study is to assess conventional and low temperature dual fuel combustion in light- and heavy-duty multi-cylinder compression ignition engines in…
(more)
▼ The goal of this study is to assess conventional and low temperature dual fuel combustion in light- and heavy-duty multi-cylinder compression
ignition engines in terms of combustion characterization, performance, and emissions. First, a light-duty compression
ignition engine is converted to a dual fuel engine and instrumented for in-cylinder pressure measurements. The primary fuels, methane and propane, are each introduced into the system by means of fumigation before the turbocharger, ensuring the air-fuel composition is well-mixed. Experiments are performed at 2.5, 5, 7.5, and 10 bar BMEP at an engine speed of 1800 RPM. Heat release analyses reveal that the
ignition delay and subsequent combustion processes are dependent on the primary fuel type and concentration, pilot quantity, and loading condition. At low load, diesel-ignited propane yields longer
ignition delay periods than diesel-ignited methane, while at high load the reactivity of propane is more pronounced, leading to shorter
ignition delays. At high load (BMEP = 10 bar), the rapid heat release associated with diesel-ignited propane appears to occur even before pilot injection, possibly indicating auto-
ignition of the propane-air mixture. Next, a modern, heavy-duty compression
ignition engine is commissioned with an open architecture controller and instrumented for in-cylinder pressure measurements. Initial diesel-ignited propane dual fuel experiments (fumigated before the turbocharger) at 1500 RPM reveal that the maximum percent energy substitution (PES) of propane is limited to 86, 60, 33, and 25 percent at 5, 10, 15, and 20 bar BMEP, respectively. Fueling strategy, injection strategy, exhaust gas recirculation (EGR) rate, and intake boost pressure are varied in order to maximize the PES of propane at 10 bar BMEP, which increases from 60 PES to 80 PES of propane. Finally, diesel-ignited propane dual fuel low temperature combustion (LTC) is implemented using early injection timings (50 DBTDC) at 5 bar BMEP. A sweep of injection timings from 10 DBTDC to 50 DBTDC reveals the transition from conventional to low temperature dual fuel combustion, indicated by ultra-low NO
x and smoke emissions. Optimization of the dual fuel LTC concept yields less than 0.02 g/kW-hr NO
x and 0.06 FSN smoke at 93 PES of propane.
Advisors/Committee Members: Sundar R. Krishnan (chair), Kalyan K. Srinivasan (chair), Rogelio Luck (committee member), D. Keith Walters (committee member).
Subjects/Keywords: compression ignition; propane; combustion; dual fuel; LTC
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CSE |
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Manager
APA (6th Edition):
Polk, A. C. (2013). Detailed characterization of conventional and low temperature dual fuel combustion in compression ignition engines. (Doctoral Dissertation). Mississippi State University. Retrieved from http://sun.library.msstate.edu/ETD-db/theses/available/etd-04012013-092845/ ;
Chicago Manual of Style (16th Edition):
Polk, Andrew C. “Detailed characterization of conventional and low temperature dual fuel combustion in compression ignition engines.” 2013. Doctoral Dissertation, Mississippi State University. Accessed April 18, 2021.
http://sun.library.msstate.edu/ETD-db/theses/available/etd-04012013-092845/ ;.
MLA Handbook (7th Edition):
Polk, Andrew C. “Detailed characterization of conventional and low temperature dual fuel combustion in compression ignition engines.” 2013. Web. 18 Apr 2021.
Vancouver:
Polk AC. Detailed characterization of conventional and low temperature dual fuel combustion in compression ignition engines. [Internet] [Doctoral dissertation]. Mississippi State University; 2013. [cited 2021 Apr 18].
Available from: http://sun.library.msstate.edu/ETD-db/theses/available/etd-04012013-092845/ ;.
Council of Science Editors:
Polk AC. Detailed characterization of conventional and low temperature dual fuel combustion in compression ignition engines. [Doctoral Dissertation]. Mississippi State University; 2013. Available from: http://sun.library.msstate.edu/ETD-db/theses/available/etd-04012013-092845/ ;
Georgia Tech
25.
Miller, Christopher M.
Effects of microstructure and chemistry on the ignition sensitivity of PBX under shock loading.
Degree: PhD, Mechanical Engineering, 2019, Georgia Tech
URL: http://hdl.handle.net/1853/62297
► The ignition sensitivity of heterogeneous energetic materials subject to shock loading is analyzed using both a Lagrangian and Eulerian computational framework. The specific focus here…
(more)
▼ The
ignition sensitivity of heterogeneous energetic materials
subject to shock loading is analyzed using both a Lagrangian and Eulerian computational framework. The specific focus here is on the various microstructure heterogeneities (including cracks, granular anisotropy, voids, and aluminum additives) and their relative contributions to the development of critical hotspots and macroscale detonation behavior characteristics, such as the run distance to detonation. A probabilistic approach is developed by generating statistically equivalent microstructure sample sets (SEMSS) and measuring the
ignition behavior of each one under similar impact conditions. By varying the material and microstructural characteristics in a controlled fashion, the contribution to
ignition of each specific type of microstructural defects is rank-ordered. The Lagrangian-based cohesive finite element method (CFEM) is used to track material response prior to the onset of chemical reaction. A probability threshold is proposed based on a modified form of the Hugh James and Walker-Wasley energy-based
ignition criterions. The computations focus on both 100% packed energetic grains (HMX) as well as aluminized polymer-bonded explosives (APBXs). The exact physical mechanisms governing the development of hotspots are quantified, and the friction is found to be the dominant dissipation mechanism. The Sandia National Laboratories Eulerian hydrocode, CTH, is then used to simulate the entire shock to detonation transition (SDT) of pressed HMX. The run-to-detonation distance is predicted as a function of shock pressure. The initial probability analysis is expanded upon to generate a predictive map of the SDT threshold for both 2D and 3D samples. The probability thresholds proposed in this study serve as a useful design metric and may directly influence future shock experimentation as well as the development of new insensitive high explosives design metric and may directly influence future shock experimentation as well as the development of new insensitive high explosives.
Advisors/Committee Members: Zhou, Min (advisor), Neu, Richard (committee member), Zhu, Ting (committee member), Rimoli, Julian (committee member), Yarrington, Cole (committee member).
Subjects/Keywords: Ignition sensitivity; Detonation; HMX; PBX; Microstructure
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APA (6th Edition):
Miller, C. M. (2019). Effects of microstructure and chemistry on the ignition sensitivity of PBX under shock loading. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/62297
Chicago Manual of Style (16th Edition):
Miller, Christopher M. “Effects of microstructure and chemistry on the ignition sensitivity of PBX under shock loading.” 2019. Doctoral Dissertation, Georgia Tech. Accessed April 18, 2021.
http://hdl.handle.net/1853/62297.
MLA Handbook (7th Edition):
Miller, Christopher M. “Effects of microstructure and chemistry on the ignition sensitivity of PBX under shock loading.” 2019. Web. 18 Apr 2021.
Vancouver:
Miller CM. Effects of microstructure and chemistry on the ignition sensitivity of PBX under shock loading. [Internet] [Doctoral dissertation]. Georgia Tech; 2019. [cited 2021 Apr 18].
Available from: http://hdl.handle.net/1853/62297.
Council of Science Editors:
Miller CM. Effects of microstructure and chemistry on the ignition sensitivity of PBX under shock loading. [Doctoral Dissertation]. Georgia Tech; 2019. Available from: http://hdl.handle.net/1853/62297
Anna University
26.
Manivannan, A.
Studies on extended expansion lean burn spark ignition
engine operating with gasoline; -.
Degree: Mechanical Engineering, 2014, Anna University
URL: http://shodhganga.inflibnet.ac.in/handle/10603/27605
► In the development of internal combustion engines there has been a newlinecontinuous effort to reduce fuel consumption and exhaust emissions newlineImproved fuel efficiency with reduced…
(more)
▼ In the development of internal combustion engines
there has been a newlinecontinuous effort to reduce fuel
consumption and exhaust emissions newlineImproved fuel efficiency
with reduced exhaust gas emissions is one of the newlinemajor
challenges that engineers and scientists in the automotive industry
and newlineare facing Also in recent years there has been great
concern that the internal newlinecombustion engine is predominantly
responsible for atmospheric pollution newlinewhich is detrimental
to human health and environmental damage newlineConsequently
research engineers have been striving to reduce the quantity of
newlinepollutants emitted from exhaust system without sacrificing
power and fuel newlineconsumption newline newline
Reference p.175-182
Advisors/Committee Members: Ramaprabhu, R.
Subjects/Keywords: burn spark ignition; engine operating; mechanical engineering
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APA (6th Edition):
Manivannan, A. (2014). Studies on extended expansion lean burn spark ignition
engine operating with gasoline; -. (Thesis). Anna University. Retrieved from http://shodhganga.inflibnet.ac.in/handle/10603/27605
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Manivannan, A. “Studies on extended expansion lean burn spark ignition
engine operating with gasoline; -.” 2014. Thesis, Anna University. Accessed April 18, 2021.
http://shodhganga.inflibnet.ac.in/handle/10603/27605.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Manivannan, A. “Studies on extended expansion lean burn spark ignition
engine operating with gasoline; -.” 2014. Web. 18 Apr 2021.
Vancouver:
Manivannan A. Studies on extended expansion lean burn spark ignition
engine operating with gasoline; -. [Internet] [Thesis]. Anna University; 2014. [cited 2021 Apr 18].
Available from: http://shodhganga.inflibnet.ac.in/handle/10603/27605.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Manivannan A. Studies on extended expansion lean burn spark ignition
engine operating with gasoline; -. [Thesis]. Anna University; 2014. Available from: http://shodhganga.inflibnet.ac.in/handle/10603/27605
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Anna University
27.
Sudesh kumar M P.
Experimental and theoretical analysis of performance and
emissions of a diesel engine running on ignition improver
blend;.
Degree: performance and emissions of a diesel engine running
on ignition improver blend, 2014, Anna University
URL: http://shodhganga.inflibnet.ac.in/handle/10603/26236
► Diesel engines are a major power source in the transport sector due newlineto its increased torque and high thermal efficiency But the emissions newlineproduced from…
(more)
▼ Diesel engines are a major power source in the
transport sector due newlineto its increased torque and high
thermal efficiency But the emissions newlineproduced from these
engines pose serious challenges, which has prompted the
newlineautomotive researchers to search for alternatives The
addition of an ignition newlineimprover in the diesel fuel is one
of the possible approaches to improve the newlineengine performance
and reduces the emissions To identify the potential of
newlineignition improvers experiments have been performed in a
diesel engine to newlinestudy the engine performance and exhaust
emissions newline newline newline
Reference p.140-147
Advisors/Committee Members: Devaradjane G.
Subjects/Keywords: diesel engine; ignition improver blend; mechanical engineering
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Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
P, S. k. M. (2014). Experimental and theoretical analysis of performance and
emissions of a diesel engine running on ignition improver
blend;. (Thesis). Anna University. Retrieved from http://shodhganga.inflibnet.ac.in/handle/10603/26236
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
P, Sudesh kumar M. “Experimental and theoretical analysis of performance and
emissions of a diesel engine running on ignition improver
blend;.” 2014. Thesis, Anna University. Accessed April 18, 2021.
http://shodhganga.inflibnet.ac.in/handle/10603/26236.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
P, Sudesh kumar M. “Experimental and theoretical analysis of performance and
emissions of a diesel engine running on ignition improver
blend;.” 2014. Web. 18 Apr 2021.
Vancouver:
P SkM. Experimental and theoretical analysis of performance and
emissions of a diesel engine running on ignition improver
blend;. [Internet] [Thesis]. Anna University; 2014. [cited 2021 Apr 18].
Available from: http://shodhganga.inflibnet.ac.in/handle/10603/26236.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
P SkM. Experimental and theoretical analysis of performance and
emissions of a diesel engine running on ignition improver
blend;. [Thesis]. Anna University; 2014. Available from: http://shodhganga.inflibnet.ac.in/handle/10603/26236
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
28.
Martin, Brandon Ray.
Pyrolysis and ignition behavior of coal, cattle biomass, and coal/cattle biomass blends.
Degree: MS, Mechanical Engineering, 2009, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-1148
► Increases in demand, lower emission standards, and reduced fuel supplies have fueled the recent effort to find new and better fuels to power the necessary…
(more)
▼ Increases in demand, lower emission standards, and reduced fuel supplies have
fueled the recent effort to find new and better fuels to power the necessary equipment for
society’s needs. Often, the fuels chosen for research are renewable fuels derived from
biomass. Current research at Texas A&M University is focused on the effectiveness of
using cattle manure biomass as a fuel source in conjunction with coal burning utilities.
The scope of this project includes fuel property analysis, pyrolysis and
ignition behavior
characteristics, combustion modeling, emissions modeling, small scale combustion
experiments, pilot scale commercial combustion experiments, and cost analysis of the
fuel usage for both feedlot biomass and dairy biomass. This paper focuses on fuel
property analysis and pyrolysis and
ignition characteristics of feedlot biomass.
Deliverables include a proximate and ultimate analysis, pyrolysis kinetics values, and
ignition temperatures of four types of feedlot biomass (low ash raw manure [LARM],
low ash partially composted manure [LAPC], high ash raw manure [HARM], and high
ash partially composted manure [HAPC]) as well as blends of each biomass with Texas
lignite coal (TXL). Activation energy results for pure samples of each fuel using the single reaction model rigorous solution were as follows: 45 kJ/mol (LARM), 43 kJ/mol
(LAPC), 38 kJ/mol (HARM), 36 kJ/mol (HAPC), and 22 kJ/mol (TXL). Using the
distributed activation energy model the activation energies were 169 kJ/mol (LARM),
175 kJ/mol (LAPC), 172 kJ/mol (HARM), 173 kJ/mol (HAPC), and 225 kJ/mol (TXL).
Ignition temperature results for pure samples of each of the fuels were as follows: 734 K
(LARM), 745 K (LAPC), 727 (HARM), 744 K (HAPC), and 592 K (TXL). There was
little difference observed between the
ignition temperatures of the 50% blends of coal
with biomass and the pure samples of coal as observed by the following results: 606 K
(LARM), 571 K (LAPC), 595 K (HARM), and 582 K (HAPC).
Advisors/Committee Members: Annamalai, Kalyan (advisor), Caton, Jerald (committee member), Mukhtar, Saqib (committee member).
Subjects/Keywords: pyrolysis; ignition; TGA
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Manager
APA (6th Edition):
Martin, B. R. (2009). Pyrolysis and ignition behavior of coal, cattle biomass, and coal/cattle biomass blends. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-1148
Chicago Manual of Style (16th Edition):
Martin, Brandon Ray. “Pyrolysis and ignition behavior of coal, cattle biomass, and coal/cattle biomass blends.” 2009. Masters Thesis, Texas A&M University. Accessed April 18, 2021.
http://hdl.handle.net/1969.1/ETD-TAMU-1148.
MLA Handbook (7th Edition):
Martin, Brandon Ray. “Pyrolysis and ignition behavior of coal, cattle biomass, and coal/cattle biomass blends.” 2009. Web. 18 Apr 2021.
Vancouver:
Martin BR. Pyrolysis and ignition behavior of coal, cattle biomass, and coal/cattle biomass blends. [Internet] [Masters thesis]. Texas A&M University; 2009. [cited 2021 Apr 18].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-1148.
Council of Science Editors:
Martin BR. Pyrolysis and ignition behavior of coal, cattle biomass, and coal/cattle biomass blends. [Masters Thesis]. Texas A&M University; 2009. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-1148
Texas A&M University
29.
Demko, Andrew Robert.
Advancements in Composite Solid Propellant Testing and Evaluation for Formulations Containing Novel Nano-Additives.
Degree: PhD, Mechanical Engineering, 2017, Texas A&M University
URL: http://hdl.handle.net/1969.1/161402
► Composite solid propellants are typically used in rocket propulsion systems due to their simplicity and relatively low cost. They are mixtures of the fuel, oxidizer,…
(more)
▼ Composite solid propellants are typically used in rocket propulsion systems due to their simplicity and relatively low cost. They are mixtures of the fuel, oxidizer, and various catalysts. Oftentimes, bonding agents and plasticizers are added to improve the mixture and propellant qualities. The advent of the nano-particle synthesis revolution allows for customized particle synthesis. This dissertation outlines two innovative experiments developed at Texas A&M University to study the combustion efficiency and the
ignition properties of composite propellants with and without advanced nano-additives.
This study first presents new insight and possible advantages unique only to closed-bomb strand burners for the testing of composite solid propellants. However, little information on the combustion efficiency has been reported with strand burner testing. The advantages of a closed-bomb burner is revealed in the present work for the first time by relating the observed pressure rise to a quantitative measure of combustion efficiency through the use of temperature change approximations. The pressure rise is an indication of the flame temperature from the propellant combustion products that mix with the inert gas (argon) in the chamber. Baseline propellants of diverse ammonium perchlorate (AP) particle size distributions were tested at 80% AP and 20% HTPB by weight. Then, using the highest-performing AP, propellants of 85% mono- and bi-modal AP distributions were tested, resulting in a clear comparison of their relative effects on the propellant burning efficiency. The pressure rise study concluded with comparing combustion efficiencies of the synthesis methods of metal oxide catalysts in both aluminized and non-aluminized AP and hydroxyl–terminated polybutadiene (HTPB) propellants. Plotting a normalized pressure rise compared and the mean test pressure indicated that the propellants with narrow AP particle size distributions burn more efficiently. Using simplified models, changes in flame temperature were calculated, and corresponding changes in the relative combustion efficiency were found. Chemical c* efficiency changes were approximated using the constant-volume strand burner for different AP particle sizes and titania synthesis methods.
The second focus is on developing a method to evaluate the
ignition delay times of similar propellant formulations.
Ignition delay time measurements on solid energetic materials lead to better fundamental understanding of the
ignition process and provide benchmark data for improving models of the
ignition process. This study focused on the validation of
ignition delay times of AP/HTPB-based solid propellants with and without aluminum and compared various metal-oxide nanoparticle catalysts. A CO2 laser with a wavelength of 10.6 μm was operated to obtain a quantifiable and reliable
ignition event over a power range of 30 to 100 W. This study developed a method to measure the
ignition delay time for AP/HTPB propellants at elevated pressures. The
ignition delay time results were compared to…
Advisors/Committee Members: Petersen, Eric L (advisor), Jacobs, Timothy (committee member), Staack, David (committee member), Mashuga, Chad (committee member).
Subjects/Keywords: AP; HTPB; Combustion Efficiency; Ignition; Delay
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APA ·
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Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Demko, A. R. (2017). Advancements in Composite Solid Propellant Testing and Evaluation for Formulations Containing Novel Nano-Additives. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/161402
Chicago Manual of Style (16th Edition):
Demko, Andrew Robert. “Advancements in Composite Solid Propellant Testing and Evaluation for Formulations Containing Novel Nano-Additives.” 2017. Doctoral Dissertation, Texas A&M University. Accessed April 18, 2021.
http://hdl.handle.net/1969.1/161402.
MLA Handbook (7th Edition):
Demko, Andrew Robert. “Advancements in Composite Solid Propellant Testing and Evaluation for Formulations Containing Novel Nano-Additives.” 2017. Web. 18 Apr 2021.
Vancouver:
Demko AR. Advancements in Composite Solid Propellant Testing and Evaluation for Formulations Containing Novel Nano-Additives. [Internet] [Doctoral dissertation]. Texas A&M University; 2017. [cited 2021 Apr 18].
Available from: http://hdl.handle.net/1969.1/161402.
Council of Science Editors:
Demko AR. Advancements in Composite Solid Propellant Testing and Evaluation for Formulations Containing Novel Nano-Additives. [Doctoral Dissertation]. Texas A&M University; 2017. Available from: http://hdl.handle.net/1969.1/161402
Texas A&M University
30.
Pemelton, John.
Shock-Tube Study of Methane Ignition with NO2 and N2O.
Degree: MS, Mechanical Engineering, 2012, Texas A&M University
URL: http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-10188
► NOx produced during combustion can persist in the exhaust gases of a gas turbine engine in quantities significant to induce regulatory concerns. There has been…
(more)
▼ NOx produced during combustion can persist in the exhaust gases of a gas turbine engine in quantities significant to induce regulatory concerns. There has been much research which has led to important insights into NOx chemistry. One method of NOx reduction is exhaust gas recirculation. In exhaust gas recirculation, a portion of the exhaust gases that exit are redirected to the inlet air stream that enters the combustion chamber, along with fuel. Due to the presence of NOx in the exhaust gases which are subsequently introduced into the burner, knowledge of the effects of NOx on combustion is advantageous. Contrary to general NOx research, little has been conducted to investigate the sensitizing effects of NO2 and N2O addition to methane/oxygen combustion.
Experiments were made with dilute and real fuel air mixtures of CH4/O2/Ar with the addition of NO2 and N2O. The real fuel air concentrations were made with the addition of NO2 only. The equivalence ratios of mixtures made were 0.5, 1 and 2. The experimental pressure range was 1 - 44 atm and the temperature range tested was 1177 – 2095 K. The additives NO2 and N2O were added in concentrations from 831 ppm to 3539 ppm. The results of the mixtures with NO2 have a reduction in
ignition delay time across the pressure ranges tested, and the mixtures with N2O show a similar trend. At 1.3 atm, the NO2 831 ppm mixture shows a 65% reduction and shows a 75% reduction at 30 atm. The NO2 mixtures showed a higher decrease in
ignition time than the N2O mixtures. The real fuel air mixture also showed a reduction.
Sensitivity Analyses were performed. The two most dominant reactions in the NO2 mixtures are the reaction O+H2 = O+OH and the reaction CH3+NO2 = CH3O+NO. The presence of this second reaction is the means by which NO2 decreases
ignition delay time, which is indicated in the experimental results. The reaction produces CH3O which is reactive and can participate in chain propagating reactions, speeding up
ignition.
The two dominant reactions for the N2O mixture are the reaction O+H2 = O+OH and, interestingly, the other dominant reaction is the reverse of the initiation reaction in the N2O-mechanism: O+N2+M = N2O+M. The reverse of this reaction is the direct oxidation of nitrous oxide. The O produced in this reaction can then speed up
ignition by partaking in propagation reactions, which was experimentally observed.
Advisors/Committee Members: Petersen, Eric L. (advisor), Annamalai, Kalyan (committee member), Bowersox, Rodney (committee member).
Subjects/Keywords: Ignition Delay; NOx chemistry; Shock Tube
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APA (6th Edition):
Pemelton, J. (2012). Shock-Tube Study of Methane Ignition with NO2 and N2O. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-10188
Chicago Manual of Style (16th Edition):
Pemelton, John. “Shock-Tube Study of Methane Ignition with NO2 and N2O.” 2012. Masters Thesis, Texas A&M University. Accessed April 18, 2021.
http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-10188.
MLA Handbook (7th Edition):
Pemelton, John. “Shock-Tube Study of Methane Ignition with NO2 and N2O.” 2012. Web. 18 Apr 2021.
Vancouver:
Pemelton J. Shock-Tube Study of Methane Ignition with NO2 and N2O. [Internet] [Masters thesis]. Texas A&M University; 2012. [cited 2021 Apr 18].
Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-10188.
Council of Science Editors:
Pemelton J. Shock-Tube Study of Methane Ignition with NO2 and N2O. [Masters Thesis]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-10188
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