subject:(Combustion modeling)

University of Alberta

1. Shahbakhti, Mahdi. Modeling and experimental study of an HCCI engine for combustion timing control.

Degree: PhD, Department of Mechanical Engineering, 2009, University of Alberta

URL: https://era.library.ualberta.ca/files/x346d4343

► Homogeneous Charge Compression Ignition (HCCI) is a promising method for combustion engines to provide a substantial reduction in fuel consumption and formation of both nitrogen… (more)

Subjects/Keywords: Modeling; Combustion engines; HCCI

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APA (6^th Edition):

Shahbakhti, M. (2009). Modeling and experimental study of an HCCI engine for combustion timing control. (Doctoral Dissertation). University of Alberta. Retrieved from https://era.library.ualberta.ca/files/x346d4343

Chicago Manual of Style (16^th Edition):

Shahbakhti, Mahdi. “Modeling and experimental study of an HCCI engine for combustion timing control.” 2009. Doctoral Dissertation, University of Alberta. Accessed April 15, 2021. https://era.library.ualberta.ca/files/x346d4343.

MLA Handbook (7^th Edition):

Shahbakhti, Mahdi. “Modeling and experimental study of an HCCI engine for combustion timing control.” 2009. Web. 15 Apr 2021.

Vancouver:

Shahbakhti M. Modeling and experimental study of an HCCI engine for combustion timing control. [Internet] [Doctoral dissertation]. University of Alberta; 2009. [cited 2021 Apr 15]. Available from: https://era.library.ualberta.ca/files/x346d4343.

Council of Science Editors:

Shahbakhti M. Modeling and experimental study of an HCCI engine for combustion timing control. [Doctoral Dissertation]. University of Alberta; 2009. Available from: https://era.library.ualberta.ca/files/x346d4343

University of Connecticut

2. Yang, Hongtao. Emission Modeling in Turbulent Premixed Flames.

Degree: MS, Mechanical Engineering, 2013, University of Connecticut

URL: https://opencommons.uconn.edu/gs_theses/479

► Turbulent lean premixed combustion now plays a predominant role in reducing emission of pollutants such as NOx. For turbulent premixed flames located in the… (more)

▼ Turbulent lean premixed combustion now plays a predominant role in reducing emission of pollutants such as NOx. For turbulent premixed flames located in the thin-reaction-zones regime, small-scale eddies could penetrate into the preheat zone of the flames and enhance the mixing process. In this study, the effects of small-scale turbulence on emission (NOx and CO) formation in premixed flame fronts are investigated through the incorporation of turbulence induced diffusion in the preheat zone of one-dimensional premixed flames. One-dimensional methane/air premixed flames are simulated with the 53-species GRI-Mech 3.0 mechanism at both atmospheric and engine conditions with different turbulence intensities. It is found that the NO generated in flame fronts deceases with increasing intensity of small-scale turbulence and the effect is more profound at high pressures. At high pressures, the turbulence induced diffusion in the preheat zone can reduce the NOx formation in flame fronts by more than 40%. On the other hand, the CO mass fraction in flame fronts increases with increasing intensity of small-scale turbulence. In the cases considered, the CO mass fraction in the flame fronts can increase by more than 55%. In addition, a flamelet-based approach that accounts for the flame thickening effects has been formulated to simulate NOx and CO formation in turbulent lean premixed combustion. In this approach, the species NO and CO are transported and solved in a simulation with chemical source terms being pre-calculated from 1-D premixed flames with detailed chemical kinetics and turbulence induced diffusion. The NO source term can be quantified by its formation in flame fronts and its formation rate in post-flame region. The CO source term can be calculated through its mass fraction at flame fronts, its mass fraction in the post-flame region and an oxidation time scale. The effect of heat loss on NO formation has been studied by investigate the relation between post-flame NO formation rate and flame temperature. Meanwhile, the effect of turbulent-chemistry interaction on NO were studied. The flamelet-based emission model has been implemented into Fluent and 3-Dimensional simulations were conducted in a combustion rig. Advisors/Committee Members: Tianfeng Lu, Tai-Hsi Fan, Zhuyin Ren.

Subjects/Keywords: combustion; emission modeling; NOx; flamelet; premixed flame

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APA (6^th Edition):

Yang, H. (2013). Emission Modeling in Turbulent Premixed Flames. (Masters Thesis). University of Connecticut. Retrieved from https://opencommons.uconn.edu/gs_theses/479

Chicago Manual of Style (16^th Edition):

Yang, Hongtao. “Emission Modeling in Turbulent Premixed Flames.” 2013. Masters Thesis, University of Connecticut. Accessed April 15, 2021. https://opencommons.uconn.edu/gs_theses/479.

MLA Handbook (7^th Edition):

Yang, Hongtao. “Emission Modeling in Turbulent Premixed Flames.” 2013. Web. 15 Apr 2021.

Vancouver:

Yang H. Emission Modeling in Turbulent Premixed Flames. [Internet] [Masters thesis]. University of Connecticut; 2013. [cited 2021 Apr 15]. Available from: https://opencommons.uconn.edu/gs_theses/479.

Council of Science Editors:

Yang H. Emission Modeling in Turbulent Premixed Flames. [Masters Thesis]. University of Connecticut; 2013. Available from: https://opencommons.uconn.edu/gs_theses/479

Colorado State University

3. L'Orange, Christian. Development of numerical tools for characterizing and quantifying biomass cookstove impact, The.

Degree: PhD, Mechanical Engineering, 2013, Colorado State University

URL: http://hdl.handle.net/10217/80160

► Biomass cookstove use can be damaging to both human health and the global climate. In an effort to minimize these impacts, numerous programs are working… (more)

▼ Biomass cookstove use can be damaging to both human health and the global climate. In an effort to minimize these impacts, numerous programs are working to disseminate improved biomass cookstoves. However, few programs have achieved extensive success towards improving either climate or health. One reason programs have only resulted in limited improvements has been the sector's inability to quantify cookstove performance. A numeric tool has been developed for characterizing biomass cookstove performance. This dissertation documents the development of that tool. The document is comprised of three components: (i) the critical analysis of the uncertainty associated with current methods for cookstove field-testing, (ii) the development and validation of a probabilistic impact model for biomass cookstoves, and (iii) the application of these numerical tools to quantify cookstove impact. Biomass cookstoves have traditionally been evaluated empirically. Cookstoves are tested in both the field and the laboratory, with each approach having advantages and limitations. Neither laboratory nor field testing are sufficient, however, for quantifying cookstove impact. Field-testing provides invaluable data on cookstove use but is limited by the large variability typically seen in the results. Drawing conclusions from field tests is challenging due to this variability. Many groups attempt to address testing variability by increasing the number of test replicates conducted. A numeric model was developed to determine the number of test replicates required to quantify cookstove performance in field settings. Because of the large number of test replicates required to have statistical confidence in field-based data, an improved method of quantifying biomass cookstove performance is needed. Therefore, to address this need a probabilistic Monte Carlo prediction model was developed to quantify cookstove performance. The intention of the model is to serve as a tool for predicting the impact of various cookstove designs. The model integrates various facets of existing cookstove performance knowledge in more a cohesive fashion. Model simulations were compared to experimental studies to validate this approach. Numeric tools are only valuable if they result in useful information; for example, information that allows informed decisions to be made. The potential of numeric models to provide valuable information for cookstove programs has been demonstrated by simulating the performance of multiple cookstove designs. Three improved cookstoves designs have been compared to a traditional three-stone fire. Each design was evaluated for multiple scenarios, use patterns, and locations. The impact of each design (in regard to climate and health) was then quantified and monetized. This exercise yielded two important findings. First, consideration of location and context is critical when comparing the performance of cookstoves. Second, numeric models can be used as highly informative tools to support decision-making in the cookstove sector. Empirical… Advisors/Committee Members: Willson, Bryan (advisor), DeFoort, Morgan (advisor), Marchese, Anthony (committee member), Volckens, John (committee member).

Subjects/Keywords: biomass; combustion; cookstove; modeling; Monte Carlo

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APA (6^th Edition):

L'Orange, C. (2013). Development of numerical tools for characterizing and quantifying biomass cookstove impact, The. (Doctoral Dissertation). Colorado State University. Retrieved from http://hdl.handle.net/10217/80160

Chicago Manual of Style (16^th Edition):

L'Orange, Christian. “Development of numerical tools for characterizing and quantifying biomass cookstove impact, The.” 2013. Doctoral Dissertation, Colorado State University. Accessed April 15, 2021. http://hdl.handle.net/10217/80160.

MLA Handbook (7^th Edition):

L'Orange, Christian. “Development of numerical tools for characterizing and quantifying biomass cookstove impact, The.” 2013. Web. 15 Apr 2021.

Vancouver:

L'Orange C. Development of numerical tools for characterizing and quantifying biomass cookstove impact, The. [Internet] [Doctoral dissertation]. Colorado State University; 2013. [cited 2021 Apr 15]. Available from: http://hdl.handle.net/10217/80160.

Council of Science Editors:

L'Orange C. Development of numerical tools for characterizing and quantifying biomass cookstove impact, The. [Doctoral Dissertation]. Colorado State University; 2013. Available from: http://hdl.handle.net/10217/80160

New Jersey Institute of Technology

4. Fong, Daniel. Mathematical models of combustion at high pressure.

Degree: PhD, Mathematical Sciences, 2012, New Jersey Institute of Technology

URL: https://digitalcommons.njit.edu/dissertations/320

► In this dissertation, we develop new mathematical theories of flame propagation that are valid at elevated, or extreme, pressures. Of particular interest is the… (more)

▼ In this dissertation, we develop new mathematical theories of flame propagation that are valid at elevated, or extreme, pressures. Of particular interest is the regime of burning in which the pressure exceeds the critical pressure of the species undergoing chemical reaction. Fluids and flames are known to behave differently under these extreme conditions as opposed to atmospheric pressure. The focus of this dissertation is to investigate these differences by deriving reduced models that contain the unique features. In the first part of this dissertation, we analyze the structure of laminar diffusion flames at high pressure in the limit of large activation energy for the particular configuration of a steady flame in counterflow. We consider a dense fluid in which normal Fickian diffusion of the fuel is limited, and thermal diffusion, i.e., the Soret effect, is the dominant mechanism for fuel mass transport. Temperature and species profiles, as well as flame temperature and location, are determined as a function of Damköhler number and Soret diffusion coefficient. In particular, we find that oxidant is entirely consumed by the flame, while some fuel leaks through. For light fuels, the fuel profile is found to have a local peak on the oxidant side as a result of thermal diffusion. Our analysis includes a description of extinction phenomenon, including explicit criteria in terms of the Soret diffusion coefficient, ratio of temperature of the two streams, and the Damköhler number at extinction. In the second part of this dissertation, we derive an asymptotic theory of laminar premixed flames in high density fluids in the limit of large activation energy. The model is intended to provide insights into the structure and dynamics of deflagration waves in high pressure, dense fluids where normal Fickian diffusion is limited. In such cases, particularly under conditions exceeding the thermodynamic critical point of the fluid, the primary mode of species transport is through thermal diffusion, i.e., the Soret effect. Such a model for diffusive transport is considered, and we derive a model with an explicit dependence on the Soret effect for a one-step overall reaction. The density is assumed sufficiently high to adopt a constant density formulation. The local reaction-diffusion structure is found to be fundamentally different from that of an ideal gas with Fickian diffusion, which results in new conditions relating the equations for thermal and mass transport in the bulk flow. The model is used to investigate the basic structure of planar flames, as well as their stability. Stability boundaries are identified that mark the transition from planar to either steady, spatially periodic structures, or time-dependent modes of propagation. The combined effects of the Soret diffusion coefficient and Lewis number are discussed. Furthermore, a weakly nonlinear analysis of the derived model is carried out, resulting in a modified Kuramoto-Sivashinsky (K-S) equation, accounting for effects of Soret Diffusion. Linear… Advisors/Committee Members: John Kenneth Bechtold, Shahriar Afkhami, Michael R. Booty.

Subjects/Keywords: Combustion; Mathematical modeling; Reacting flows; Asymptotics; Mathematics

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APA (6^th Edition):

Fong, D. (2012). Mathematical models of combustion at high pressure. (Doctoral Dissertation). New Jersey Institute of Technology. Retrieved from https://digitalcommons.njit.edu/dissertations/320

Chicago Manual of Style (16^th Edition):

Fong, Daniel. “Mathematical models of combustion at high pressure.” 2012. Doctoral Dissertation, New Jersey Institute of Technology. Accessed April 15, 2021. https://digitalcommons.njit.edu/dissertations/320.

MLA Handbook (7^th Edition):

Fong, Daniel. “Mathematical models of combustion at high pressure.” 2012. Web. 15 Apr 2021.

Vancouver:

Fong D. Mathematical models of combustion at high pressure. [Internet] [Doctoral dissertation]. New Jersey Institute of Technology; 2012. [cited 2021 Apr 15]. Available from: https://digitalcommons.njit.edu/dissertations/320.

Council of Science Editors:

Fong D. Mathematical models of combustion at high pressure. [Doctoral Dissertation]. New Jersey Institute of Technology; 2012. Available from: https://digitalcommons.njit.edu/dissertations/320

University of Iowa

5. Depman, Albert J., III. Stoker boiler CFD modeling improvements through alternative heat exchanger modeling.

Degree: MS, Mechanical Engineering, 2014, University of Iowa

URL: https://ir.uiowa.edu/etd/4609

► Accurate models and realistic simulations are essential in developing cleaner and more efficient coal- and biomass-fired boilers. Using the CFD simulation software Fluent The… (more)

▼ Accurate models and realistic simulations are essential in developing cleaner and more efficient coal- and biomass-fired boilers. Using the CFD simulation software Fluent The University of Iowa created a model of an industrial boiler that adequately compares the practice of co-firing biomass and coal against firing only coal. The simulations used in this comparison, show significant circulation zones and an unrealistic temperature profile inside the boiler heat exchanger region. This model is effective for comparing the relative decrease in emissions when co-firing with biomass versus exclusively coal combustion, but it does not present a realistic simulation of biomass or coal combustion. The purpose of the current work is to develop a more realistic baseline coal combustion model. Calculations for the proximate and ultimate analysis of coal, as well as properties necessary for energy and mass flux computations, have been updated in the current model. The fuel bed model - a simple two-dimensional distribution of energy and mass fluxes from the grate - was kept the same due to the complexities of fuel bed modeling. Simulation boundary conditions and flow models were tested and modified to determine the most realistic model settings. The geometry and mesh grid of the boiler model were also varied in an attempt to fix problematic areas. Several approaches were implemented in an effort to reduce the circulation zones and generate a realistic temperature profile. The negative energy source term in the boiler representing the energy removed by the water pipes in the heat exchanger was analyzed, and different configurations of this sink were tested. Finally, the heat exchanger models built in to Fluent were studied and implemented. These models proved to be the most effective in reducing recirculation zones and decreasing high temperature gradients. While the current model of the coal-fired boiler has a higher overall temperature than the previous one, circulation zones are almost completely eliminated, the flow path has been improved, and the temperature profile in the boiler is more realistic. Advisors/Committee Members: Ratner, Albert (supervisor).

Subjects/Keywords: Boiler; CFD; Combustion; Fluent; Modeling; Mechanical Engineering

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APA (6^th Edition):

Depman, Albert J., I. (2014). Stoker boiler CFD modeling improvements through alternative heat exchanger modeling. (Masters Thesis). University of Iowa. Retrieved from https://ir.uiowa.edu/etd/4609

Chicago Manual of Style (16^th Edition):

Depman, Albert J., III. “Stoker boiler CFD modeling improvements through alternative heat exchanger modeling.” 2014. Masters Thesis, University of Iowa. Accessed April 15, 2021. https://ir.uiowa.edu/etd/4609.

MLA Handbook (7^th Edition):

Depman, Albert J., III. “Stoker boiler CFD modeling improvements through alternative heat exchanger modeling.” 2014. Web. 15 Apr 2021.

Vancouver:

Depman, Albert J. I. Stoker boiler CFD modeling improvements through alternative heat exchanger modeling. [Internet] [Masters thesis]. University of Iowa; 2014. [cited 2021 Apr 15]. Available from: https://ir.uiowa.edu/etd/4609.

Council of Science Editors:

Depman, Albert J. I. Stoker boiler CFD modeling improvements through alternative heat exchanger modeling. [Masters Thesis]. University of Iowa; 2014. Available from: https://ir.uiowa.edu/etd/4609

Michigan Technological University

6. Loveland, Dustin P. DEVELOPMENT OF A PREDICTIVE COMBUSTION MODEL OF A SPARK IGNITED ENGINE WITH GASOLINE DIRECT INJECTION, VARIABLE VALVE TIMING, DURATION AND LIFT TECHNOLOGIES.

Degree: MS, Department of Mechanical Engineering-Engineering Mechanics, 2012, Michigan Technological University

URL: https://digitalcommons.mtu.edu/etd-restricted/111

► There is a need by engine manufactures for computationally efficient and accurate predictive combustion modeling tools for integration in engine simulation software for the… (more)

Subjects/Keywords: Combustion; Development; Engine; Modeling; Mechanical Engineering

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APA (6^th Edition):

Loveland, D. P. (2012). DEVELOPMENT OF A PREDICTIVE COMBUSTION MODEL OF A SPARK IGNITED ENGINE WITH GASOLINE DIRECT INJECTION, VARIABLE VALVE TIMING, DURATION AND LIFT TECHNOLOGIES. (Masters Thesis). Michigan Technological University. Retrieved from https://digitalcommons.mtu.edu/etd-restricted/111

Chicago Manual of Style (16^th Edition):

Loveland, Dustin P. “DEVELOPMENT OF A PREDICTIVE COMBUSTION MODEL OF A SPARK IGNITED ENGINE WITH GASOLINE DIRECT INJECTION, VARIABLE VALVE TIMING, DURATION AND LIFT TECHNOLOGIES.” 2012. Masters Thesis, Michigan Technological University. Accessed April 15, 2021. https://digitalcommons.mtu.edu/etd-restricted/111.

MLA Handbook (7^th Edition):

Loveland, Dustin P. “DEVELOPMENT OF A PREDICTIVE COMBUSTION MODEL OF A SPARK IGNITED ENGINE WITH GASOLINE DIRECT INJECTION, VARIABLE VALVE TIMING, DURATION AND LIFT TECHNOLOGIES.” 2012. Web. 15 Apr 2021.

Vancouver:

Loveland DP. DEVELOPMENT OF A PREDICTIVE COMBUSTION MODEL OF A SPARK IGNITED ENGINE WITH GASOLINE DIRECT INJECTION, VARIABLE VALVE TIMING, DURATION AND LIFT TECHNOLOGIES. [Internet] [Masters thesis]. Michigan Technological University; 2012. [cited 2021 Apr 15]. Available from: https://digitalcommons.mtu.edu/etd-restricted/111.

Council of Science Editors:

Loveland DP. DEVELOPMENT OF A PREDICTIVE COMBUSTION MODEL OF A SPARK IGNITED ENGINE WITH GASOLINE DIRECT INJECTION, VARIABLE VALVE TIMING, DURATION AND LIFT TECHNOLOGIES. [Masters Thesis]. Michigan Technological University; 2012. Available from: https://digitalcommons.mtu.edu/etd-restricted/111

Colorado School of Mines

7. Nguyen, Thu. CFD modeling of methane flame, turbulence, and obstacle interaction applied to a longwall coal mine.

Degree: MS(M.S.), Mechanical Engineering, 2020, Colorado School of Mines

URL: http://hdl.handle.net/11124/174135

► The formation of explosive gas zones (EGZs) forming from flammable vapors, gases, or dust pose safety hazards to many industries. An EGZ ignition could occur… (more)

▼ The formation of explosive gas zones (EGZs) forming from flammable vapors, gases, or dust pose safety hazards to many industries. An EGZ ignition could occur by faulty electrical equipment, hot streaks from worn bits on a shearer cutting hard rock, rock-on-rock frictional sparks, heat, or fires and result in an explosion, and/or detonation. Agriculture, oil and gas, chemical, and energy industries experience methane-air or organic dust explosion hazards. In many cases, explosions may occur in confined areas with obstacles in the path of flame expansion. By studying the effects of obstacle shape and size on flame propagation and turbulence, a more complete understanding of the interaction of the flame and fluid dynamics has been achieved. Obstacle shape, turbulence model, and spark location were investigated using a single obstacle and flame interaction in the model. Reynolds Averaged Navier Stokes (RANS) models were tested to determine if these simplified turbulence models could capture the flame dynamics and propagation velocities using fewer computational resources compared to the higher fidelity Large Eddy Simulation (LES) turbulence model. Obstacle shapes were varied to examine the impact of shape on methane flame propagation. Results showed that square obstacles caused faster flame propagation around the obstacle compared to hexagons and circles. The square had an average flame speed 26% faster than the circle, and the hexagon was 16% faster than the circle using a k-ω model. Modeling results indicate that variation of the spark location by as a distance as small as 10% of the obstacle diameter can result in a significant difference in flame propagation velocity. Comparing to RANS, an LES turbulence model only increases computational time by 25%. Therefore, the LES turbulence model was used in modeling a simplified 2D longwall mine combustion model. Achieving reasonable computational times while maintaining general flame propagation trends was the main goal of modeling an explosion in a full-scale longwall mine. Investigating different methods of modeling the gob inside the mine showed that a porous media model would not be able to capture effects from turbulence or handle a reacting flow due to a Darcy Flow assumption. As a result, the gob was modeled as a fluid zone with discrete obstacles. Results from the 2D mine model with combustion overpredicted the pressure compared to a 3D model but was still able to track the propagation of the pressure front well when compared to a 3D model. By simplifying the model to 2D, computational time was reduced to three days, compared to three weeks for the 3D model, to simulate a 35ms interval after ignition. Advisors/Committee Members: Bogin, Gregory E. (advisor), Brune, Jürgen F. (advisor), Porter, Jason M. (committee member), Rickey, Kelly (committee member).

Subjects/Keywords: flame; turbulence; methane-air combustion; CFD modeling

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APA (6^th Edition):

Nguyen, T. (2020). CFD modeling of methane flame, turbulence, and obstacle interaction applied to a longwall coal mine. (Masters Thesis). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/174135

Chicago Manual of Style (16^th Edition):

Nguyen, Thu. “CFD modeling of methane flame, turbulence, and obstacle interaction applied to a longwall coal mine.” 2020. Masters Thesis, Colorado School of Mines. Accessed April 15, 2021. http://hdl.handle.net/11124/174135.

MLA Handbook (7^th Edition):

Nguyen, Thu. “CFD modeling of methane flame, turbulence, and obstacle interaction applied to a longwall coal mine.” 2020. Web. 15 Apr 2021.

Vancouver:

Nguyen T. CFD modeling of methane flame, turbulence, and obstacle interaction applied to a longwall coal mine. [Internet] [Masters thesis]. Colorado School of Mines; 2020. [cited 2021 Apr 15]. Available from: http://hdl.handle.net/11124/174135.

Council of Science Editors:

Nguyen T. CFD modeling of methane flame, turbulence, and obstacle interaction applied to a longwall coal mine. [Masters Thesis]. Colorado School of Mines; 2020. Available from: http://hdl.handle.net/11124/174135

Virginia Tech

8. Haber, Ludwig Christian. An investigation into the origin, measurement and application of chemiluminescent light emissions from premixed flames.

Degree: MS, Mechanical Engineering, 2000, Virginia Tech

URL: http://hdl.handle.net/10919/31472

► The chemiluminescent species CH* and OH* are studied in premixed methane combustion to investigate the possible application of their light emissions in gas turbine combustion… (more)

Subjects/Keywords: combustion; modeling; chemiluminescence

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APA (6^th Edition):

Haber, L. C. (2000). An investigation into the origin, measurement and application of chemiluminescent light emissions from premixed flames. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/31472

Chicago Manual of Style (16^th Edition):

Haber, Ludwig Christian. “An investigation into the origin, measurement and application of chemiluminescent light emissions from premixed flames.” 2000. Masters Thesis, Virginia Tech. Accessed April 15, 2021. http://hdl.handle.net/10919/31472.

MLA Handbook (7^th Edition):

Haber, Ludwig Christian. “An investigation into the origin, measurement and application of chemiluminescent light emissions from premixed flames.” 2000. Web. 15 Apr 2021.

Vancouver:

Haber LC. An investigation into the origin, measurement and application of chemiluminescent light emissions from premixed flames. [Internet] [Masters thesis]. Virginia Tech; 2000. [cited 2021 Apr 15]. Available from: http://hdl.handle.net/10919/31472.

Council of Science Editors:

Haber LC. An investigation into the origin, measurement and application of chemiluminescent light emissions from premixed flames. [Masters Thesis]. Virginia Tech; 2000. Available from: http://hdl.handle.net/10919/31472

9. Muller, Mathieu. Modélisation de la combustion de gouttes d'aluminium dans les conditions d'un moteur fusée à propergol solide : Modeling of the aluminum droplet combustion under the conditions of a solid rocket motor.

Degree: Docteur es, Physique énergétique, 2019, Sorbonne université

URL: http://www.theses.fr/2019SORUS267

►

L’objet de cette thèse est d’étudier la combustion de gouttes d’aluminium (Al) dans les conditions d’un moteur-fusée à propergol solide. On a besoin de modéliser… (more)

▼

L’objet de cette thèse est d’étudier la combustion de gouttes d’aluminium (Al) dans les conditions d’un moteur-fusée à propergol solide. On a besoin de modéliser ce processus pour évaluer le temps de combustion et la taille des résidus car leur caractérisation dans les conditions réelles est très complexe. Un modèle de combustion d’une goutte en approche multiphysique à symétrie sphérique a été développé tenant compte de nombreux phénomènes physico-chimiques. Ce modèle a été validé et utilisé pour étudier les mécanismes réactionnels en phase gazeuse et en surface. Des simulations en ambiance contrôlée ont été réalisées et les résultats obtenus sont comparés aux données expérimentales de la littérature. L’étude de la combustion de deux classes de gouttes d’Al (particule primaire et agglomérat) en ambiance typique d’un booster Ariane 5 a été menée afin d’évaluer l’effet des différentes cinétiques hétérogènes de surface sur le processus de combustion simulé. Suite à l’intégration du modèle de surface réactive dans le code CEDRE de l’ONERA, les simulations de la combustion ont été poursuivies en approche bidimensionnelle axisymétrique afin d’étudier l’influence de la calotte en surface de la goutte et de la convection des gaz oxydants. La simulation de la combustion établie des deux classes de goutte à 5 et 9 MPa à différents stades d’avancement a permis d’évaluer les caractéristiques principales de la combustion et d’en déduire une loi de combustion globale. Enfin, la phase de chauffage avant établissement de la combustion a été étudiée pour compléter la caractérisation.

The purpose of this thesis is to study the aluminum (Al) droplet combustion in solid rocket motor propellant. We need to model this process to evaluate the burning time and the residues length because their characterization in real conditions is very complex. A combustion model of a single droplet with a multiphysical spherical approach has been developed taking into account various phenomena. This model has been validated and used to study gaseous and surface mechanisms. Simulations in controlled atmospheres were made and the results were compared to experimental data. The study of the combustion of two particle classes (primary particle and agglomerate) under conditions typical for the Ariane 5 solid booster was conducted to evaluate the effect of different heterogeneous surface kinetics on the simulated combustion process. After the integration of the reactive surface model in the ONERA code CEDRE, simulations of the combustion using a two-dimensional axisymmetric approach were made to study the impact of the cap on the droplet surface and the convection velocity of oxidizers. By simulating the established combustion of two droplet classes at two pressures (5 and 9 MPa) in different stages of combustion, we evaluated main characteristics of the combustion and we deducted a global burning law. Finally, the heating of the droplet before an established combustion was studied to complete the characterization.

Advisors/Committee Members: Giovangigli, Vincent (thesis director).

Subjects/Keywords: Combustion d'une goutte d'aluminium; Modélisation; Résidu de combustion; Ambiance contrôlée; Ambiance propulseur; Loi de combustion; Aluminium droplet combustion; Modeling; Combustion residues; Controlled atmosphere; Combustion law; 621.4356

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APA (6^th Edition):

Muller, M. (2019). Modélisation de la combustion de gouttes d'aluminium dans les conditions d'un moteur fusée à propergol solide : Modeling of the aluminum droplet combustion under the conditions of a solid rocket motor. (Doctoral Dissertation). Sorbonne université. Retrieved from http://www.theses.fr/2019SORUS267

Chicago Manual of Style (16^th Edition):

Muller, Mathieu. “Modélisation de la combustion de gouttes d'aluminium dans les conditions d'un moteur fusée à propergol solide : Modeling of the aluminum droplet combustion under the conditions of a solid rocket motor.” 2019. Doctoral Dissertation, Sorbonne université. Accessed April 15, 2021. http://www.theses.fr/2019SORUS267.

MLA Handbook (7^th Edition):

Muller, Mathieu. “Modélisation de la combustion de gouttes d'aluminium dans les conditions d'un moteur fusée à propergol solide : Modeling of the aluminum droplet combustion under the conditions of a solid rocket motor.” 2019. Web. 15 Apr 2021.

Vancouver:

Muller M. Modélisation de la combustion de gouttes d'aluminium dans les conditions d'un moteur fusée à propergol solide : Modeling of the aluminum droplet combustion under the conditions of a solid rocket motor. [Internet] [Doctoral dissertation]. Sorbonne université; 2019. [cited 2021 Apr 15]. Available from: http://www.theses.fr/2019SORUS267.

Council of Science Editors:

Muller M. Modélisation de la combustion de gouttes d'aluminium dans les conditions d'un moteur fusée à propergol solide : Modeling of the aluminum droplet combustion under the conditions of a solid rocket motor. [Doctoral Dissertation]. Sorbonne université; 2019. Available from: http://www.theses.fr/2019SORUS267

Georgia Tech

10. Kim, Sayop. Advancing turbulent spray and combustion models for compression ignition engine simulations.

Degree: PhD, Aerospace Engineering, 2019, Georgia Tech

URL: http://hdl.handle.net/1853/61216

► This thesis seeks to investigate the turbulent mixing influence on spray atomization and combustion processes encountered in compression ignition diesel engines. Despite greater thermal efficiency… (more)

▼ This thesis seeks to investigate the turbulent mixing influence on spray atomization and combustion processes encountered in compression ignition diesel engines. Despite greater thermal efficiency of diesel engine than spark ignition engine, the nature of stratified air-fuel mixture and non-premixed flame gives rise to unacceptable levels of nitrogen oxides (NOx) and particulate matter (PM), thus the use of diesel engines has often been limited to heavy-duty vehicle and industrial power sources. However, recent advancement in diesel engine combustion strategies, e.g. low temperature combustion (LTC), has demonstrated promising pathways towards improvement in the engine-out pollutants. Therefore, particularly in the effort of computer-aided engine design tasks, such a new engine design concept requires more accurate modeling techniques applicable over a broader range of engine operating conditions than those of conventional engine strategies. In the notion of challenges in new engine operating conditions, this thesis aims to present successful implementation of improvement in numerical modeling techniques in high-pressure spray atomization and resulting turbulent spray flame of interest. Three-dimensional Computational Fluid Dynamics (CFD) in in-cylinder turbu- lent combustion is considered an integral part of engine design progress, but rather a cost-prohibitive to apply over a broad range of engine relevant conditions. In spite of successful use of existing spray atomization modeling, prior researchers have pointed out some degree of failure in LTC targeted injection strategies. Furthermore, finite rate and strong nonlinearity of chemistry influenced by local turbulent mixing still re- main in challenges to account for in cost-efficient CFD analysis. In this context, a new attempt of hybrid spray primary breakup modeling is presented and demonstrated in successful application aimed at LTC technique. In addition, the Representative Interactive Flamelets (RIF) model with aid of multi-flamelets approach is extensively assessed in terms of predictive capability against classical combustion model. The combustion model employed in this study are fully examined in the general diesel combustion metric, e.g., ignition delay and flame lift-off length as well as newly sug- gested test metric, combustion recession. The combustion recession has been recently idenfied, but still remain largely unknown. Since the governing physics of this phenomenon is characterized by turbulent mixing coupled with finite rate chemistry, this can be considered as a relevant test metric for turbulent combustion models. In addition, very recent experimental studies have introduced a new non-sooting diesel combustion technique by manipulating direct injection method. The ducted fuel injection (DFI) has thus been demonstrated with its potential of low soot emissions. Knowing that the duct equipped ahead of injector nozzle was identifed to enhance turbulent mixing, investigations of DFI combustion may prove the effectiveness of turbulece-chemistry… Advisors/Committee Members: Genzale, Caroline (advisor), Jagoda, Jechiel (advisor), Oefelein, Joseph (committee member), Sun, Wenting (committee member), Alexeev, Alexander (committee member), Lucchini, Tommaso (committee member).

Subjects/Keywords: Diesel engine; CFD; Spray modeling; Turbulence-chemistry interaction; Combustion modeling

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APA (6^th Edition):

Kim, S. (2019). Advancing turbulent spray and combustion models for compression ignition engine simulations. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/61216

Chicago Manual of Style (16^th Edition):

Kim, Sayop. “Advancing turbulent spray and combustion models for compression ignition engine simulations.” 2019. Doctoral Dissertation, Georgia Tech. Accessed April 15, 2021. http://hdl.handle.net/1853/61216.

MLA Handbook (7^th Edition):

Kim, Sayop. “Advancing turbulent spray and combustion models for compression ignition engine simulations.” 2019. Web. 15 Apr 2021.

Vancouver:

Kim S. Advancing turbulent spray and combustion models for compression ignition engine simulations. [Internet] [Doctoral dissertation]. Georgia Tech; 2019. [cited 2021 Apr 15]. Available from: http://hdl.handle.net/1853/61216.

Council of Science Editors:

Kim S. Advancing turbulent spray and combustion models for compression ignition engine simulations. [Doctoral Dissertation]. Georgia Tech; 2019. Available from: http://hdl.handle.net/1853/61216

KTH

11. Duyar, Serkan. Modeling diesel combustion in heavy duty engine using detailed chemistry approach and CFD.

Degree: Heat and Power Technology, 2014, KTH

URL: http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-149478

► Emission and fuel consumption are among the key parameters when designing a combustion system. Combustion CFD can assist in this task only if good… (more)

Subjects/Keywords: CFD; AVL Fire; combustion modeling; emission modeling; reduced chemistry approach

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APA (6^th Edition):

Duyar, S. (2014). Modeling diesel combustion in heavy duty engine using detailed chemistry approach and CFD. (Thesis). KTH. Retrieved from http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-149478

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Duyar, Serkan. “Modeling diesel combustion in heavy duty engine using detailed chemistry approach and CFD.” 2014. Thesis, KTH. Accessed April 15, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-149478.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Duyar, Serkan. “Modeling diesel combustion in heavy duty engine using detailed chemistry approach and CFD.” 2014. Web. 15 Apr 2021.

Vancouver:

Duyar S. Modeling diesel combustion in heavy duty engine using detailed chemistry approach and CFD. [Internet] [Thesis]. KTH; 2014. [cited 2021 Apr 15]. Available from: http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-149478.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Duyar S. Modeling diesel combustion in heavy duty engine using detailed chemistry approach and CFD. [Thesis]. KTH; 2014. Available from: http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-149478

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Indian Institute of Science

12. Biju Kumar, K S. Role Of Hydrogen Injection Temperature On The Combustion Instability Of Cryogenic Rocket Engine.

Degree: PhD, Faculty of Engineering, 2014, Indian Institute of Science

URL: http://etd.iisc.ac.in/handle/2005/2297

► Physical mechanism for high frequency instability in cryogenic engines at low hydrogen injection temperature has been a subject of debate for long time. Experimental and… (more)

▼ Physical mechanism for high frequency instability in cryogenic engines at low hydrogen injection temperature has been a subject of debate for long time. Experimental and early developmental studies revealed no instabilities and it was only much later when liquid hydrogen at lower initial temperature (~50 to 100 K) was injected into the combustion chamber that instabilities were detected. From the compilations of the experimental data related to the instability of cryogenic engines by Hulka and Hutt, it was found that the instability was strongly connected to the temperature of hydrogen. Experiments conducted with hydrogen temperature ramping from a higher value to lower values indicated that the temperatures in excess of 90 K favor stability under most practical operating conditions. Even though this has been known for over forty years, there has been no clear and simple explanation for this. Many physical mechanisms have been hypothesized to explain how temperature ramping causes instability, but all appear to have limited range of applicability. Current understanding of cryogenic engine combustion instability has been achieved through a combination of experimental investigation and approximate analytical models as well as CFD tools. Various researchers have tried to link the low hydrogen injection temperature combustion instability phenomena with various potential mechanisms for combustion instability. They involve coupling of combustion acoustics with atomization, vaporization, mixing, chemical kinetics or any combination of these processes. Various studies related to the effect of recess, injector hydrodynamics, acoustic damping of gas liquid scheme injectors and effect of drop size distribution on the stability characteristics of cryogenic engines were compiled in the thesis. Several researchers examined fuel droplet vaporization as the rate controlling mechanism. Recently a new method for the evaluation of stability characteristics of the engine using model chamber were proposed by Russians and this is based on mixing as the rate controlling mechanism. Pros and cons of this method were discussed. Some people examined the combustion instability of rocket engines based on chemistry dynamics. A considerable amount of analytical and numerical studies were carried out by various researchers for finding out the cause of combustion instability. Because of the limitations of their analysis, they could not successfully explain the cause of combustion instability at low hydrogen injection temperature. A compilation of previous numerical studies were carried out. A number of researchers have applied CFD in the study of combustion instabilities in liquid propellant rocket engines. In the present thesis, a theoretical model has been developed based on the vaporization of droplets to predict the stability characteristics of the engine. The proposed concept focuses on three dimensional simulation of combustion instability for giving some meaningful explanations for the experimental work presented in the literature. In the… Advisors/Committee Members: Paul, P J (advisor), Ranjan, N K S (advisor).

Subjects/Keywords: Liquid Propellant Rocket; Cryogenic Rocket Engines; Combustion Instability; Cryogenic Engines - Combustion Instability; Hydrogen Injection Temperature Combustion Instability; Cryogenic Engines - Combustion Modeling; Combustion Instability; Heat Engineering

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APA (6^th Edition):

Biju Kumar, K. S. (2014). Role Of Hydrogen Injection Temperature On The Combustion Instability Of Cryogenic Rocket Engine. (Doctoral Dissertation). Indian Institute of Science. Retrieved from http://etd.iisc.ac.in/handle/2005/2297

Chicago Manual of Style (16^th Edition):

Biju Kumar, K S. “Role Of Hydrogen Injection Temperature On The Combustion Instability Of Cryogenic Rocket Engine.” 2014. Doctoral Dissertation, Indian Institute of Science. Accessed April 15, 2021. http://etd.iisc.ac.in/handle/2005/2297.

MLA Handbook (7^th Edition):

Biju Kumar, K S. “Role Of Hydrogen Injection Temperature On The Combustion Instability Of Cryogenic Rocket Engine.” 2014. Web. 15 Apr 2021.

Vancouver:

Biju Kumar KS. Role Of Hydrogen Injection Temperature On The Combustion Instability Of Cryogenic Rocket Engine. [Internet] [Doctoral dissertation]. Indian Institute of Science; 2014. [cited 2021 Apr 15]. Available from: http://etd.iisc.ac.in/handle/2005/2297.

Council of Science Editors:

Biju Kumar KS. Role Of Hydrogen Injection Temperature On The Combustion Instability Of Cryogenic Rocket Engine. [Doctoral Dissertation]. Indian Institute of Science; 2014. Available from: http://etd.iisc.ac.in/handle/2005/2297

13. Sainte-Rose, Bruno. Simulations numériques d'écoulements réactifs massivement décollés par une approche hybride RANS/LES : Numerical simulations of separated reactive flow using an hybrid RANS-LES approach.

Degree: Docteur es, Energétique, 2010, Châtenay-Malabry, Ecole centrale de Paris

URL: http://www.theses.fr/2010ECAP0014

►

Les premières simulations numériques d'écoulements réactifs sur des configurationscomplexes ont été réalisées à l'aide d'approches RANS (Reynolds Averaged Navier Stokes). Ces dernières, bien adaptées aux… (more)

▼

Les premières simulations numériques d'écoulements réactifs sur des configurationscomplexes ont été réalisées à l'aide d'approches RANS (Reynolds Averaged Navier Stokes). Ces dernières, bien adaptées aux écoulements de type couches limites attachées et relativement peu coûteuses en temps de calcul, ne donnent accès qu'à des résultats stationnaires qui s'éloignent parfois de la réalité. Pour réaliser des simulations instationnaires d'écoulements, les méthodes de type LES (Large Eddy Simulation) – plus précises mais plus coûteuses – sont de plus en plus utilisées. Cependant, ces méthodes sont mal adaptées à la simulation de la dynamique pariétale, car elles nécessitent un effort de maillage souvent prohibitif près de la paroi. Cette thèse est consacrée au développement dans le code CEDRE (code de simulation d'écoulements réactifs complexes de l'Onera) d'une méthode hybride RANS/LES, appelée Delayed Detached Eddy Simulation (DDES), et à son application à des écoulements réactifs massivement décollés. Après une étape de validation sur des couches limites attachées, la DDES a été appliquée à la simulation des écoulements inerte et réactif dans une chambre de combustion en forme de marche descendante (A3C) et comparée aux résultats des approches RANS et LES classiques, ainsi qu'aux résultats expérimentaux. Cette méthode a ensuite permis de réaliser l'étude de la dynamique de l'écoulement réactif décollé dans la tuyère ATAC montée sur le banc cryotechnique MASCOTTE de l'Onera.

The first numerical simulations of reactive flows on complex configurations were performed using RANS (Reynolds Averaged Navier Stokes) approaches. These methods, which are well adapted to attached boundary layer flows and relatively not expensive in computation time, provide only steady results, which may not correctly reproduce reality. For unsteady flow simulations, LES (Large Eddy Simulation) method – more accurate but more expensive – are increasingly employed. However, these approaches are poorly suited to simulate wall turbulence since they often require a prohibitive meshing effort close to the wall. This PhD thesis is devoted to the development in the CEDRE code (Onera code for the simulation of complex reactive flows) of a hybrid RANS/LES approach, called Delayed Detached Eddy Simulation (DDES) and to its application to massively separated reactive flows. After a step of validation on attached boundary layers, the DDES is applied to the simulation of the inert and reactive flows in a backward facing step combustor (A3C) and compared to the results obtained by RANS and LES approaches, as well as to experimental results. The DDES has then been used to study the dynamics of the separated reactive flow in the ATAC nozzle mounted on the cryotechnic MASCOTTE facility of Onera.

Advisors/Committee Members: Dupoirieux, Francis (thesis director).

Subjects/Keywords: Modélisation de la turbulence; Combustion turbulente; Écoulements surdétendus; Turbulence modeling; Turbulent combustion; Overexpanded flows

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APA (6^th Edition):

Sainte-Rose, B. (2010). Simulations numériques d'écoulements réactifs massivement décollés par une approche hybride RANS/LES : Numerical simulations of separated reactive flow using an hybrid RANS-LES approach. (Doctoral Dissertation). Châtenay-Malabry, Ecole centrale de Paris. Retrieved from http://www.theses.fr/2010ECAP0014

Chicago Manual of Style (16^th Edition):

Sainte-Rose, Bruno. “Simulations numériques d'écoulements réactifs massivement décollés par une approche hybride RANS/LES : Numerical simulations of separated reactive flow using an hybrid RANS-LES approach.” 2010. Doctoral Dissertation, Châtenay-Malabry, Ecole centrale de Paris. Accessed April 15, 2021. http://www.theses.fr/2010ECAP0014.

MLA Handbook (7^th Edition):

Sainte-Rose, Bruno. “Simulations numériques d'écoulements réactifs massivement décollés par une approche hybride RANS/LES : Numerical simulations of separated reactive flow using an hybrid RANS-LES approach.” 2010. Web. 15 Apr 2021.

Vancouver:

Sainte-Rose B. Simulations numériques d'écoulements réactifs massivement décollés par une approche hybride RANS/LES : Numerical simulations of separated reactive flow using an hybrid RANS-LES approach. [Internet] [Doctoral dissertation]. Châtenay-Malabry, Ecole centrale de Paris; 2010. [cited 2021 Apr 15]. Available from: http://www.theses.fr/2010ECAP0014.

Council of Science Editors:

Sainte-Rose B. Simulations numériques d'écoulements réactifs massivement décollés par une approche hybride RANS/LES : Numerical simulations of separated reactive flow using an hybrid RANS-LES approach. [Doctoral Dissertation]. Châtenay-Malabry, Ecole centrale de Paris; 2010. Available from: http://www.theses.fr/2010ECAP0014

14. Stefanin Volpiani, Pedro. Modèle de plissement dynamique pour la simulation aux grandes échelles de la combustion turbulente prémelangée : Dynamic wrinkling flame model for large eddy simulations of turbulent premixed combustion.

Degree: Docteur es, Combustion, 2017, Université Paris-Saclay (ComUE)

URL: http://www.theses.fr/2017SACLC005

►

Avec l’accroissement considérable de la puissance de calcul, les simulations aux grandes échelles (SGE) sont maintenant utilisées de façon routinière dans de nombreuses applications d’ingénierie.… (more)

▼

Avec l’accroissement considérable de la puissance de calcul, les simulations aux grandes échelles (SGE) sont maintenant utilisées de façon routinière dans de nombreuses applications d’ingénierie. Les modèles de combustion usuels utilisés dans les SGE sont le plus souvent basés sur une hypothèse d’équilibre entre le mouvement des structures turbulentes et le plissement de la surface de la flamme. Ils s’écrivent alors sous forme d’expressions algébriques fonctions de grandeurs connues aux échelles résolues ainsi que de paramètres dont l’ajustement est à la charge de l’utilisateur selon la configuration étudiée et les conditions opératoires. Le modèle dynamique récemment développé ajuste automatiquement au cours du calcul les paramètres de modélisation qui peuvent alors dépendre du temps et de l’espace. Cette thèse présente une étude détaillée d’un modèle dynamique pour la simulation aux grandes échelles de la combustion turbulente prémélangée. L’objectif est de caractériser, explorer les avantages et les inconvénients, appliquer et valider le modèle dynamique dans plusieurs configurations.

Large eddy simulation (LES) is currently applied in a wide range of engineering applications. Classical LES combustion models are based on algebraic expressions and assume equilibrium between turbulence and flame wrinkling which is generally not verified in many circumstances as the flame is laminar at early stages and progressively wrinkled by turbulent motions. In practice, this conceptual drawback has a strong consequence: every computation needs its own set of constants, i.e. any small change in the operating conditions or in the geometry requires an adjustment of model parameters. The dynamic model recently developed adjust automatically the flame wrinkling factor from the knowledge of resolved scales. Widely used to describe the unresolved turbulent transport, the dynamic approach remains underexplored in combustion despite its interesting potential. This thesis presents a detailed study of a dynamic wrinkling factor model for large eddy simulation of turbulent premixed combustion. The goal of this thesis is to characterize, unveil pros and cons, apply and validate the dynamic modeling in different flow configurations.

Advisors/Committee Members: Veynante, Denis (thesis director), Schmitt, Thomas (thesis director).

Subjects/Keywords: Modèle dynamique; Combustion turbulente; Simulation aux grandes échelles; Dynamic modeling; Turbulent combustion; Large eddy simulation

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APA (6^th Edition):

Stefanin Volpiani, P. (2017). Modèle de plissement dynamique pour la simulation aux grandes échelles de la combustion turbulente prémelangée : Dynamic wrinkling flame model for large eddy simulations of turbulent premixed combustion. (Doctoral Dissertation). Université Paris-Saclay (ComUE). Retrieved from http://www.theses.fr/2017SACLC005

Chicago Manual of Style (16^th Edition):

Stefanin Volpiani, Pedro. “Modèle de plissement dynamique pour la simulation aux grandes échelles de la combustion turbulente prémelangée : Dynamic wrinkling flame model for large eddy simulations of turbulent premixed combustion.” 2017. Doctoral Dissertation, Université Paris-Saclay (ComUE). Accessed April 15, 2021. http://www.theses.fr/2017SACLC005.

MLA Handbook (7^th Edition):

Stefanin Volpiani, Pedro. “Modèle de plissement dynamique pour la simulation aux grandes échelles de la combustion turbulente prémelangée : Dynamic wrinkling flame model for large eddy simulations of turbulent premixed combustion.” 2017. Web. 15 Apr 2021.

Vancouver:

Stefanin Volpiani P. Modèle de plissement dynamique pour la simulation aux grandes échelles de la combustion turbulente prémelangée : Dynamic wrinkling flame model for large eddy simulations of turbulent premixed combustion. [Internet] [Doctoral dissertation]. Université Paris-Saclay (ComUE); 2017. [cited 2021 Apr 15]. Available from: http://www.theses.fr/2017SACLC005.

Council of Science Editors:

Stefanin Volpiani P. Modèle de plissement dynamique pour la simulation aux grandes échelles de la combustion turbulente prémelangée : Dynamic wrinkling flame model for large eddy simulations of turbulent premixed combustion. [Doctoral Dissertation]. Université Paris-Saclay (ComUE); 2017. Available from: http://www.theses.fr/2017SACLC005

Universitat Politècnica de València

15. Winklinger, Johannes Franz. Implementation of a combustion model based on the flamelet concept and its application to turbulent reactive sprays .

Degree: 2015, Universitat Politècnica de València

URL: http://hdl.handle.net/10251/48488

► El modelado CFD se ha convertido en una herramienta aceptada y ampliamente utilizada en el ámbito del diseño de motores de combustión interna alternativos. Los… (more)

▼ El modelado CFD se ha convertido en una herramienta aceptada y ampliamente utilizada en el ámbito del diseño de motores de combustión interna alternativos. Los modelos de combustión avanzados ayudan a comprender los fenómenos complejos químicos y físicos del proceso de combustión y aportan información detallada que no se puede obtener con experimentos. Indudablemente, el modelado del proceso de combustión turbulenta parcialmente premezclada característico de los chorros Diesel es particularmente difícil y por lo tanto es un tema de gran interés para la comunidad científica. Los retos más importantes del modelado de este tipo de llamas son la predicción del proceso del auto-encendido, caracterizado por el tiempo de retraso, y la estructura de la llama cuasi-estacionaria con su característica longitud de lift-off. Estos dos parámetros globales de los chorros Diesel son importantes por varios aspectos. Primero, es relativamente sencillo medir estos dos parámetros y por lo tanto utilizarlos para la validación de modelos y segundo, son factores determinantes en el proceso de la combustión en un motor. El auto-encendido marca el inicio de la tasa de liberación de calor y la longitud de lift-off desempeña un papel fundamental en la formación de hollín. El mecanismo de estabilización de la llama en la zona del lift-off todavía no es bien conocido aunque existen diferentes teorías en la literatura, por lo que su modelado es en la actualidad un reto no resuelto. De acuerdo con el contexto descrito previamente, en este trabajo se pretende implementar un modelo de combustión integrado en un solver RANS utilizando la plataforma CFD OpenFOAM de código abierto. El modelo propuesto está basado en el concepto de flamelets usando una química detallada combinado con funciones de probabilidad determinadas a priori (presumed-PDF) para considerar el efecto de interacción entre la química y las características del flujo turbulento, que implica hipótesis importantes. En primer lugar, con el concepto flamelet se asume que una llama Diesel turbulenta quema localmente como un conjunto de llamas laminares de difusión de flujos opuestos. En segundo lugar se asume que las fluctuaciones de las propiedades introducidas por el flujo turbulento, que son las responsables de los fenómenos de interacción entre la química y la turbulencia durante la combustión, siguen un comportamiento estadístico en el tiempo de acuerdo a una distribución de probabilidad conocida a priori. Los fenómenos complejos del auto-encendido de hidrocarburos exigen el uso de mecanismo químicos detallados para recuperar satisfactoriamente los tiempos de retraso del auto-encendido en un rango amplio de condiciones termoquímicas. Una estrategia de interés para mantener los costes computacionales dentro de límites aceptables consiste en pre-tabular los resultados del cálculo de la química en tablas. Los parámetros independientes de estas tablas son la fracción de mezcla, la variable de progreso y la tasa de disipación escalar. Además, la hipótesis de que la distribuciones de… Advisors/Committee Members: Novella Rosa, Ricardo (advisor).

Subjects/Keywords: Combustion modeling; Turbulent combustion; Reactive sprays; Lifted flame; CFD; OpenFOAM; Presumed PDF; Flamelet concept

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APA (6^th Edition):

Winklinger, J. F. (2015). Implementation of a combustion model based on the flamelet concept and its application to turbulent reactive sprays . (Doctoral Dissertation). Universitat Politècnica de València. Retrieved from http://hdl.handle.net/10251/48488

Chicago Manual of Style (16^th Edition):

Winklinger, Johannes Franz. “Implementation of a combustion model based on the flamelet concept and its application to turbulent reactive sprays .” 2015. Doctoral Dissertation, Universitat Politècnica de València. Accessed April 15, 2021. http://hdl.handle.net/10251/48488.

MLA Handbook (7^th Edition):

Winklinger, Johannes Franz. “Implementation of a combustion model based on the flamelet concept and its application to turbulent reactive sprays .” 2015. Web. 15 Apr 2021.

Vancouver:

Winklinger JF. Implementation of a combustion model based on the flamelet concept and its application to turbulent reactive sprays . [Internet] [Doctoral dissertation]. Universitat Politècnica de València; 2015. [cited 2021 Apr 15]. Available from: http://hdl.handle.net/10251/48488.

Council of Science Editors:

Winklinger JF. Implementation of a combustion model based on the flamelet concept and its application to turbulent reactive sprays . [Doctoral Dissertation]. Universitat Politècnica de València; 2015. Available from: http://hdl.handle.net/10251/48488

Georgia Tech

16. Erickson, Robert R. A Numerical Investigation on the Influence of Engine Shape and Mixing Processes on Wave Engine Performance.

Degree: PhD, Aerospace Engineering, 2005, Georgia Tech

URL: http://hdl.handle.net/1853/6819

► Wave engines are a class of unsteady, air-breathing propulsion devices that use an intermittent combustion process to generate thrust. The inherently simple mechanical design of… (more)

▼ Wave engines are a class of unsteady, air-breathing propulsion devices that use an intermittent combustion process to generate thrust. The inherently simple mechanical design of the wave engine allows for a relatively low cost per unit propulsion system, yet unsatisfactory overall performance has severely limited the development of commercially successful wave engines. The primary objective of this investigation was to develop a more detailed physical understanding of the influence of gas dynamic nonlinearities, unsteady combustion processes, and engine shape on overall wave engine performance. Within this study, several numerical models were developed and applied to wave engines and related applications. The first portion of this investigation examined the influence of duct shape on driven oscillations in acoustic compression devices, which represent a simplified physical system closely related in several ways to the wave engine. A numerical model based on an application of the Galerkin method was developed to simulate large amplitude, one-dimensional acoustic waves driven in closed ducts. Results from this portion of the investigation showed that gas-dynamic nonlinearities significantly influence the properties of driven oscillations by transferring acoustic energy from the fundamental driven mode into higher harmonic modes. The second portion of this investigation presented and analyzed results from a numerical model of wave engine dynamics based on the quasi one-dimensional conservation equations in addition to separate sub-models for mixing and heat release. This model was then used to perform parametric studies of the characteristics of mixing and engine shape. The objectives of these studies were to determine the influence of mixing characteristics and engine shape on overall wave engine performance and to develop insight into the physical processes controlling overall performance trends. Results from this model showed that wave engine performance was strongly dependent on the coupling between the unsteady heat release that drives oscillations in the engine and the characteristics that determine the acoustic properties of the engine such as engine shape and mean property gradients. Simulation results showed that average thrust generation decreased dramatically when the natural acoustic mode frequencies of the engine and the frequency content of the unsteady heat release were not aligned. Advisors/Committee Members: Ben T. Zinn (Committee Chair), Jeff Jagoda (Committee Member), Rick Gaeta (Committee Member), Suresh Menon (Committee Member), Tim Lieuwen (Committee Member).

Subjects/Keywords: Combustion modeling; Wave engines; Combustion dynamics

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APA (6^th Edition):

Erickson, R. R. (2005). A Numerical Investigation on the Influence of Engine Shape and Mixing Processes on Wave Engine Performance. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/6819

Chicago Manual of Style (16^th Edition):

Erickson, Robert R. “A Numerical Investigation on the Influence of Engine Shape and Mixing Processes on Wave Engine Performance.” 2005. Doctoral Dissertation, Georgia Tech. Accessed April 15, 2021. http://hdl.handle.net/1853/6819.

MLA Handbook (7^th Edition):

Erickson, Robert R. “A Numerical Investigation on the Influence of Engine Shape and Mixing Processes on Wave Engine Performance.” 2005. Web. 15 Apr 2021.

Vancouver:

Erickson RR. A Numerical Investigation on the Influence of Engine Shape and Mixing Processes on Wave Engine Performance. [Internet] [Doctoral dissertation]. Georgia Tech; 2005. [cited 2021 Apr 15]. Available from: http://hdl.handle.net/1853/6819.

Council of Science Editors:

Erickson RR. A Numerical Investigation on the Influence of Engine Shape and Mixing Processes on Wave Engine Performance. [Doctoral Dissertation]. Georgia Tech; 2005. Available from: http://hdl.handle.net/1853/6819

University of Kentucky

17. Adam, Brittany A. INCORPORATING DYNAMIC FLAME BEHAVIOR INTO THE SCALING LAWS OF WILDLAND FIRE SPREAD.

Degree: 2015, University of Kentucky

URL: https://uknowledge.uky.edu/me_etds/54

► A challenge for fire researchers is obtaining data from those fires that are most dangerous and costly. While it is feasible to instrument test beds,… (more)

Subjects/Keywords: scale modeling; wildland fire; combustion; fire spread; dynamic flame behavior; Heat Transfer, Combustion

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

APA (6^th Edition):

Adam, B. A. (2015). INCORPORATING DYNAMIC FLAME BEHAVIOR INTO THE SCALING LAWS OF WILDLAND FIRE SPREAD. (Doctoral Dissertation). University of Kentucky. Retrieved from https://uknowledge.uky.edu/me_etds/54

Chicago Manual of Style (16^th Edition):

Adam, Brittany A. “INCORPORATING DYNAMIC FLAME BEHAVIOR INTO THE SCALING LAWS OF WILDLAND FIRE SPREAD.” 2015. Doctoral Dissertation, University of Kentucky. Accessed April 15, 2021. https://uknowledge.uky.edu/me_etds/54.

MLA Handbook (7^th Edition):

Adam, Brittany A. “INCORPORATING DYNAMIC FLAME BEHAVIOR INTO THE SCALING LAWS OF WILDLAND FIRE SPREAD.” 2015. Web. 15 Apr 2021.

Vancouver:

Adam BA. INCORPORATING DYNAMIC FLAME BEHAVIOR INTO THE SCALING LAWS OF WILDLAND FIRE SPREAD. [Internet] [Doctoral dissertation]. University of Kentucky; 2015. [cited 2021 Apr 15]. Available from: https://uknowledge.uky.edu/me_etds/54.

Council of Science Editors:

Adam BA. INCORPORATING DYNAMIC FLAME BEHAVIOR INTO THE SCALING LAWS OF WILDLAND FIRE SPREAD. [Doctoral Dissertation]. University of Kentucky; 2015. Available from: https://uknowledge.uky.edu/me_etds/54

INP Toulouse

18. Motheau, Emmanuel. Accounting for mean flow effects in a zero-Mach number thermo-acoustic solver : application to entropy induced combustion instabilities : Prise en compte des effets d'écoulement moyen dans un solveur thermo-acoustique sous l'hypothèse Mach nul : application aux instabilités de combustion induites par l'entropie.

Degree: Docteur es, Dynamique des fluides, 2013, INP Toulouse

URL: http://www.theses.fr/2013INPT0107

►

Pratiquement toutes les chambres de combustion présentent des instabilités. Par conséquent, il est nécessaire de mieux les comprendre afin de les contrôler. Une possibilité est… (more)

▼

Pratiquement toutes les chambres de combustion présentent des instabilités. Par conséquent, il est nécessaire de mieux les comprendre afin de les contrôler. Une possibilité est de simuler l’écoulement réactif à l’intérieur d’une chambre de combustion grâce à la Simulation aux Grandes Echelles (SGE). Cependant la SGE est très coûteuse en terme de capacité de calcul. Une autre possibilité est de réduire la complexité du problème à une simple équation d’onde thermoacoustique (équation dite de Helmholtz), qui peut être résolue en fréquence comme un problème aux valeurs propres. Le couplage entre l’acoustique et la flamme est alors prise en compte au travers des modèles appropriés. Le principal problème de cette méthode est qu’elle repose sur l’hypothèse d’un nombre de Mach nul. Tous les phénomènes liés à l’écoulement moyen sont donc négligés. La présente thèse propose une nouvelle stratégie pour prendre en compte certains effets de l’écoulement dans un contexte à Mach nul. Dans une première partie, la manière la plus judicieuse d’imposer un élément présentant un écoulement très rapide est étudiée. La seconde partie se focalise sur le couplage entre l’acoustique et les hétérogénéités de température qui sont générées par la flamme et naturellement convectées par l’écoulement moyen. Ce phénomène est important car il est responsable du bruit indirect de combustion qui peut conduire à une instabilité thermoacoustique. Un nouveau type de condition limite (DECBC) est proposé afin de prendre en compte ce mécanisme dans un contexte de résolution de l’équation de Helmholtz à Mach nul. Dans la dernière partie, une chambre de combustion aéronautique présentant une instabilité mixte acoustique/entropique est étudiée. Le bénéfice des méthodes développées dans la présente thèse est testé et comparé à des calculs avec la SGE. Il est montré que les calculs avec un solveur de Helmholtz peuvent reproduire une instabilité de combustion complexe, et que cet outil s’avère avoir le potentiel pour prédire les instabilités afin de concevoir de nouvelles chambres de combustion.

Virtually all combustion chambers are subject to instabilities. Consequently there is a need to better understand them so as to control them. A possibility is to simulate the reactive flow within a combustor with the Large-Eddy Simulation (LES) method. However LES results come at a tremendous computational cost. Another route is to reduce the complexity of the problem to a simple thermoacoustic Helmholtz wave equation, which can be solved in the frequency domain as an eigenvalue problem. The coupling between the flame and the acoustics is then taken into account via proper models. The main drawback of this latter methodology is that it relies on the zero-Mach number assumption. Hence all phenomena inherent to mean flow effects are neglected. The present thesis aims to provide a novel strategy to introduce back some mean flow effects within the zero-Mach number framework. In a first part, the proper way to impose high-speed elements such as a turbine is investigated. The…

Advisors/Committee Members: Poinsot, Thierry (thesis director), Nicoud, Franck (thesis director).

Subjects/Keywords: Instabilités de combustion; Simulation Grandes Echelles; Bruit indirect de combustion; Modes mixtes; Modélisation thermoacoustique bas-ordre; Combustion instability; Large-Eddy Simulation; Indirect combustion noise; Mixed modes; Thermoacoustic modeling

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

APA (6^th Edition):

Motheau, E. (2013). Accounting for mean flow effects in a zero-Mach number thermo-acoustic solver : application to entropy induced combustion instabilities : Prise en compte des effets d'écoulement moyen dans un solveur thermo-acoustique sous l'hypothèse Mach nul : application aux instabilités de combustion induites par l'entropie. (Doctoral Dissertation). INP Toulouse. Retrieved from http://www.theses.fr/2013INPT0107

Chicago Manual of Style (16^th Edition):

Motheau, Emmanuel. “Accounting for mean flow effects in a zero-Mach number thermo-acoustic solver : application to entropy induced combustion instabilities : Prise en compte des effets d'écoulement moyen dans un solveur thermo-acoustique sous l'hypothèse Mach nul : application aux instabilités de combustion induites par l'entropie.” 2013. Doctoral Dissertation, INP Toulouse. Accessed April 15, 2021. http://www.theses.fr/2013INPT0107.

MLA Handbook (7^th Edition):

Motheau, Emmanuel. “Accounting for mean flow effects in a zero-Mach number thermo-acoustic solver : application to entropy induced combustion instabilities : Prise en compte des effets d'écoulement moyen dans un solveur thermo-acoustique sous l'hypothèse Mach nul : application aux instabilités de combustion induites par l'entropie.” 2013. Web. 15 Apr 2021.

Vancouver:

Motheau E. Accounting for mean flow effects in a zero-Mach number thermo-acoustic solver : application to entropy induced combustion instabilities : Prise en compte des effets d'écoulement moyen dans un solveur thermo-acoustique sous l'hypothèse Mach nul : application aux instabilités de combustion induites par l'entropie. [Internet] [Doctoral dissertation]. INP Toulouse; 2013. [cited 2021 Apr 15]. Available from: http://www.theses.fr/2013INPT0107.

Council of Science Editors:

Motheau E. Accounting for mean flow effects in a zero-Mach number thermo-acoustic solver : application to entropy induced combustion instabilities : Prise en compte des effets d'écoulement moyen dans un solveur thermo-acoustique sous l'hypothèse Mach nul : application aux instabilités de combustion induites par l'entropie. [Doctoral Dissertation]. INP Toulouse; 2013. Available from: http://www.theses.fr/2013INPT0107

University of Saskatchewan

19. Robson, Luke. Scalability of cone calorimeter test results for the prediction of full scale fire behavior of polyurethane foam.

Degree: 2014, University of Saskatchewan

URL: http://hdl.handle.net/10388/ETD-2014-08-1659

► The ignition and subsequent burning of polyurethane foam based mattresses poses a significant danger to life and safety in North American homes. The development of… (more)

▼ The ignition and subsequent burning of polyurethane foam based mattresses poses a significant danger to life and safety in North American homes. The development of fire models which can predict the full scale fire behavior of these mattresses using bench scale data would assist manufacturers and regulators to manage this danger in a cost effective manner. This thesis builds on previous work by the University of Saskatchewan and University of Waterloo fire research groups and focuses on the evaluation of one such scaling model, which was originally developed during the Combustion Behavior of Upholstered Furniture (CBUF) project. The evaluation of the CBUF model conducted in this thesis isolates the heat release rate (HRR) density sub-model and explores the effects of 1) cone calorimeter incident heat flux setting, 2) specimen thickness and 3) ignition location on the predictive capability of the CBUF model. To provide input for the CBUF model cone and furniture calorimeter tests were conducted. Cone calorimeter tests were conducted on foam specimen thicknesses of 2.5, 5.0, 7.5 and 10.0 cm at incident heat flux settings of 25, 35, 50 and 75 kW/m2. Furniture calorimeter tests were conducted on foam specimen thicknesses of 2.5, 5.0, 7.5 and 10.0 cm in both edge and center ignition configuration. Flame area spread rates were measured from infrared video of the furniture calorimeter tests using an automated algorithm. It was found that HRR curves predicted by the CBUF model showed good agreement with experimental results. Experimental results from tests of thinner foams were predicted with greater success than results from thicker foams, and results from edge ignition tests were predicted with greater success than results of center ignition tests. The results of this study indicated that specimen thickness and ignition location need to be considered when selecting an appropriate incident heat flux setting for producing input data for the CBUF model. Advisors/Committee Members: Torvi, David A., Bergstrom, Donald J., Sumner, David.

Subjects/Keywords: convolution integral; combustion; polyurethane foam; fire modeling; cone calorimeter; furniture calorimeter

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APA (6^th Edition):

Robson, L. (2014). Scalability of cone calorimeter test results for the prediction of full scale fire behavior of polyurethane foam. (Thesis). University of Saskatchewan. Retrieved from http://hdl.handle.net/10388/ETD-2014-08-1659

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Robson, Luke. “Scalability of cone calorimeter test results for the prediction of full scale fire behavior of polyurethane foam.” 2014. Thesis, University of Saskatchewan. Accessed April 15, 2021. http://hdl.handle.net/10388/ETD-2014-08-1659.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Robson, Luke. “Scalability of cone calorimeter test results for the prediction of full scale fire behavior of polyurethane foam.” 2014. Web. 15 Apr 2021.

Vancouver:

Robson L. Scalability of cone calorimeter test results for the prediction of full scale fire behavior of polyurethane foam. [Internet] [Thesis]. University of Saskatchewan; 2014. [cited 2021 Apr 15]. Available from: http://hdl.handle.net/10388/ETD-2014-08-1659.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Robson L. Scalability of cone calorimeter test results for the prediction of full scale fire behavior of polyurethane foam. [Thesis]. University of Saskatchewan; 2014. Available from: http://hdl.handle.net/10388/ETD-2014-08-1659

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Texas A&M University

20. Abdelgawad, Marwa. Combustion Timing Control of Natural Gas HCCI Engines Using Physics-Based Modeling and LQR Controller.

Degree: MS, Mechanical Engineering, 2012, Texas A&M University

URL: http://hdl.handle.net/1969.1/ETD-TAMU-2012-05-10968

► Homogeneous Charge Compression Ignition (HCCI) Engines hold promises of being the next generation of internal combustion engines due to their ability to produce high thermal… (more)

▼ Homogeneous Charge Compression Ignition (HCCI) Engines hold promises of being the next generation of internal combustion engines due to their ability to produce high thermal efficiencies and low emission levels. HCCI combustion is achieved through the auto-ignition of a compressed homogenous fuel-air mixture, thus making it a "fusion" between spark-ignition and compression-ignition engines. The main challenge in developing HCCI engines is the absence of a combustion trigger hence making it difficult to control its combustion timing. The aim of this research project is to model and control a natural gas HCCI engine. Since HCCI depends primarily on temperature and chemical composition of the mixture, Exhaust Gas Recirculation (EGR) is used to control ignition timing. In this research, a thermodynamical, physics-based nonlinear model is developed to capture the main features of the HCCI engine. In addition, the Modified Knock Integral Model (MKIM), used to predict ignition timing, is optimized. To validate the nonlinear model, ignition timing under varying conditions using the MKIM approach is shown to be in accordance with data acquired from a model developed using a sophisticated engine simulation program, GT-Power. Most control strategies are based on a linear model, therefore, the nonlinear model is linearized using the perturbation method. The linear model is validated by comparing its performance with the nonlinear model about a suitable operating point. The control of ignition timing can be defined as a regulation process where the goal is to force the nonlinear model to track a desired ignition timing by controlling the EGR ratio. Parameters from the linear model are used to determine the gains of the LQR controller. The performance of the controller is validated by implementing it on the nonlinear model and observing its ability to track the desired timing with 0.5% error within a certain operating range. To increase the operating range of the controller and reduce steady-state error, an integrator is added to the LQR. Finally, it is shown that the LQR controller is able to successfully reject disturbance, parameter variation, as well as noise. Advisors/Committee Members: Tafreshi, Reza (advisor), Langari, Reza (advisor), Jacobs, Timothy J. (committee member), Kundur, Deepa (committee member).

Subjects/Keywords: HCCI; Combustion Timing Control; Physics-Based Modeling; LQR

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APA (6^th Edition):

Abdelgawad, M. (2012). Combustion Timing Control of Natural Gas HCCI Engines Using Physics-Based Modeling and LQR Controller. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2012-05-10968

Chicago Manual of Style (16^th Edition):

Abdelgawad, Marwa. “Combustion Timing Control of Natural Gas HCCI Engines Using Physics-Based Modeling and LQR Controller.” 2012. Masters Thesis, Texas A&M University. Accessed April 15, 2021. http://hdl.handle.net/1969.1/ETD-TAMU-2012-05-10968.

MLA Handbook (7^th Edition):

Abdelgawad, Marwa. “Combustion Timing Control of Natural Gas HCCI Engines Using Physics-Based Modeling and LQR Controller.” 2012. Web. 15 Apr 2021.

Vancouver:

Abdelgawad M. Combustion Timing Control of Natural Gas HCCI Engines Using Physics-Based Modeling and LQR Controller. [Internet] [Masters thesis]. Texas A&M University; 2012. [cited 2021 Apr 15]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2012-05-10968.

Council of Science Editors:

Abdelgawad M. Combustion Timing Control of Natural Gas HCCI Engines Using Physics-Based Modeling and LQR Controller. [Masters Thesis]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2012-05-10968

Penn State University

21. Armold, Derrick Michael. Formulation and Characterization of Paraffin-based Solid Fuels Containing Swirl Inducing Grain Geometry And/or Energetic Additives.

Degree: 2014, Penn State University

URL: https://submit-etda.libraries.psu.edu/catalog/21836

► Rapid prototyping has developed to the point where polymers or waxes can be printed to serve as solid-fuel grains for hybrid rockets. Complex grain geometries… (more)

Subjects/Keywords: swirl injection; 3-D printing; regression rate; combustion efficiency; port modeling

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APA (6^th Edition):

Armold, D. M. (2014). Formulation and Characterization of Paraffin-based Solid Fuels Containing Swirl Inducing Grain Geometry And/or Energetic Additives. (Thesis). Penn State University. Retrieved from https://submit-etda.libraries.psu.edu/catalog/21836

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Armold, Derrick Michael. “Formulation and Characterization of Paraffin-based Solid Fuels Containing Swirl Inducing Grain Geometry And/or Energetic Additives.” 2014. Thesis, Penn State University. Accessed April 15, 2021. https://submit-etda.libraries.psu.edu/catalog/21836.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Armold, Derrick Michael. “Formulation and Characterization of Paraffin-based Solid Fuels Containing Swirl Inducing Grain Geometry And/or Energetic Additives.” 2014. Web. 15 Apr 2021.

Vancouver:

Armold DM. Formulation and Characterization of Paraffin-based Solid Fuels Containing Swirl Inducing Grain Geometry And/or Energetic Additives. [Internet] [Thesis]. Penn State University; 2014. [cited 2021 Apr 15]. Available from: https://submit-etda.libraries.psu.edu/catalog/21836.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Armold DM. Formulation and Characterization of Paraffin-based Solid Fuels Containing Swirl Inducing Grain Geometry And/or Energetic Additives. [Thesis]. Penn State University; 2014. Available from: https://submit-etda.libraries.psu.edu/catalog/21836

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Penn State University

22. Lee, Garrett Powell. Ignition and Combustion of Energetic Particles at Ultra-high Pressures and Heating Rates.

Degree: 2012, Penn State University

URL: https://submit-etda.libraries.psu.edu/catalog/15634

► Aluminum combustion research is a field of great interest currently, and has been for quite some time. To date, however, all research into the field… (more)

▼ Aluminum combustion research is a field of great interest currently, and has been for quite some time. To date, however, all research into the field of aluminum combustion has taken place at relatively low pressures, either near atmospheric or pressures found in rocketry environments, which are orders of magnitude less than the pressures to be found in a post-detonation environment such as with thermobaric weaponry. To address this lack of data, a ballistic compressor was modified to produce peak pressures of 100,000 psi and maximum heating rates exceeding 106 K/sec to simulate a post-detonation environment. A series of tests was run with 9 and 32 μm Al particles, both with and without a nickel coating. The two sizes of particles were chosen to explore the effect of diffusion versus kinetically controlled combustion at high pressures. Previous research indicated that a nickel coating on aluminum particles lowered the ignition temperature, and the Ni-coated particles were to determine if this held true at higher pressures. These tests were run at peak test pressures of 20,000, 40,000, and 60,000 psi. The results of the testing regimen demonstrated that the nickel coating did indeed lower ignition delay when compared with the uncoated particles, and overall had higher observed intensities. The 9 μm particles also had a substantially shorter ignition delay than their 32 μm counterparts. The 20,000 psi experiments produced notably lower observed light intensities in the 32 μm uncoated particles than the 40,000 psi tests, indicating that many more particles were burning at the higher pressures. The fact that the Ni-coated 32 μm particles had high observed light intensity values in both the 20 and 40,000 psi tests indicates that the nickel coated particles can burn at much lower pressures. Unfortunately, the 60,000 psi tests produced inconclusive results due to damage to the sapphire viewing windows. Advisors/Committee Members: Kenneth K Kuo, Thesis Advisor/Co-Advisor, Laura Pauley, Thesis Advisor/Co-Advisor, Karen Ann Thole, Thesis Advisor/Co-Advisor.

Subjects/Keywords: aluminum combustion; nickel coating; ballistic compressor; particle ignition; thermobaric weapon modeling

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

APA (6^th Edition):

Lee, G. P. (2012). Ignition and Combustion of Energetic Particles at Ultra-high Pressures and Heating Rates. (Thesis). Penn State University. Retrieved from https://submit-etda.libraries.psu.edu/catalog/15634

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Lee, Garrett Powell. “Ignition and Combustion of Energetic Particles at Ultra-high Pressures and Heating Rates.” 2012. Thesis, Penn State University. Accessed April 15, 2021. https://submit-etda.libraries.psu.edu/catalog/15634.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Lee, Garrett Powell. “Ignition and Combustion of Energetic Particles at Ultra-high Pressures and Heating Rates.” 2012. Web. 15 Apr 2021.

Vancouver:

Lee GP. Ignition and Combustion of Energetic Particles at Ultra-high Pressures and Heating Rates. [Internet] [Thesis]. Penn State University; 2012. [cited 2021 Apr 15]. Available from: https://submit-etda.libraries.psu.edu/catalog/15634.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Lee GP. Ignition and Combustion of Energetic Particles at Ultra-high Pressures and Heating Rates. [Thesis]. Penn State University; 2012. Available from: https://submit-etda.libraries.psu.edu/catalog/15634

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Toronto

23. Yeung, Coleman Yue. Experimental and Kinetic Modeling Study of 1-hexanol Combustion in an Opposed-flow Diffusion Flame.

Degree: 2011, University of Toronto

URL: http://hdl.handle.net/1807/31652

►

Biofuels are of particular interest as they have the potential to reduce our dependence on petroleum-derived fuels for transportation. 1-Hexanol is a promising renewable long… (more)

Subjects/Keywords: Combustion; 1-Hexanol; Kinetic Modeling; Biofuels; Oppposed-flow diffusion flame; 0542

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

APA (6^th Edition):

Yeung, C. Y. (2011). Experimental and Kinetic Modeling Study of 1-hexanol Combustion in an Opposed-flow Diffusion Flame. (Masters Thesis). University of Toronto. Retrieved from http://hdl.handle.net/1807/31652

Chicago Manual of Style (16^th Edition):

Yeung, Coleman Yue. “Experimental and Kinetic Modeling Study of 1-hexanol Combustion in an Opposed-flow Diffusion Flame.” 2011. Masters Thesis, University of Toronto. Accessed April 15, 2021. http://hdl.handle.net/1807/31652.

MLA Handbook (7^th Edition):

Yeung, Coleman Yue. “Experimental and Kinetic Modeling Study of 1-hexanol Combustion in an Opposed-flow Diffusion Flame.” 2011. Web. 15 Apr 2021.

Vancouver:

Yeung CY. Experimental and Kinetic Modeling Study of 1-hexanol Combustion in an Opposed-flow Diffusion Flame. [Internet] [Masters thesis]. University of Toronto; 2011. [cited 2021 Apr 15]. Available from: http://hdl.handle.net/1807/31652.

Council of Science Editors:

Yeung CY. Experimental and Kinetic Modeling Study of 1-hexanol Combustion in an Opposed-flow Diffusion Flame. [Masters Thesis]. University of Toronto; 2011. Available from: http://hdl.handle.net/1807/31652

Humboldt State University

24. Gill, William. Analysis of field data and spatial methods for the parametrization of a spatial duff consumption model.

Degree: MS, Environmental Systems: Mathematical Modeling, 2012, Humboldt State University

URL: http://hdl.handle.net/2148/947

► Field data collected from the consumption of organic forest soil (duff) by smoldering combustion are analyzed to determine the spatial patterns as input for a… (more)

Subjects/Keywords: Duff; Modeling; Smoldering combustion; Duff consumption; Fire behavior

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

APA (6^th Edition):

Gill, W. (2012). Analysis of field data and spatial methods for the parametrization of a spatial duff consumption model. (Masters Thesis). Humboldt State University. Retrieved from http://hdl.handle.net/2148/947

Chicago Manual of Style (16^th Edition):

Gill, William. “Analysis of field data and spatial methods for the parametrization of a spatial duff consumption model.” 2012. Masters Thesis, Humboldt State University. Accessed April 15, 2021. http://hdl.handle.net/2148/947.

MLA Handbook (7^th Edition):

Gill, William. “Analysis of field data and spatial methods for the parametrization of a spatial duff consumption model.” 2012. Web. 15 Apr 2021.

Vancouver:

Gill W. Analysis of field data and spatial methods for the parametrization of a spatial duff consumption model. [Internet] [Masters thesis]. Humboldt State University; 2012. [cited 2021 Apr 15]. Available from: http://hdl.handle.net/2148/947.

Council of Science Editors:

Gill W. Analysis of field data and spatial methods for the parametrization of a spatial duff consumption model. [Masters Thesis]. Humboldt State University; 2012. Available from: http://hdl.handle.net/2148/947

University of Wisconsin – Milwaukee

25. Tamvada, Sulekha. Modeling the Feasibility of Corn Stover Combustion as a Heat Source at Corn Ethanol Plants.

Degree: MS, Engineering, 2015, University of Wisconsin – Milwaukee

URL: https://dc.uwm.edu/etd/1085

► Alternative energy sources are of prime interest for most of the nations across the world. Rising fuel prices and depleting petroleum reserves are of… (more)

Subjects/Keywords: Biomass Combustion; Corn Stover; Ethanol; Modeling; Production Process; Mechanical Engineering

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APA (6^th Edition):

Tamvada, S. (2015). Modeling the Feasibility of Corn Stover Combustion as a Heat Source at Corn Ethanol Plants. (Thesis). University of Wisconsin – Milwaukee. Retrieved from https://dc.uwm.edu/etd/1085

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Tamvada, Sulekha. “Modeling the Feasibility of Corn Stover Combustion as a Heat Source at Corn Ethanol Plants.” 2015. Thesis, University of Wisconsin – Milwaukee. Accessed April 15, 2021. https://dc.uwm.edu/etd/1085.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Tamvada, Sulekha. “Modeling the Feasibility of Corn Stover Combustion as a Heat Source at Corn Ethanol Plants.” 2015. Web. 15 Apr 2021.

Vancouver:

Tamvada S. Modeling the Feasibility of Corn Stover Combustion as a Heat Source at Corn Ethanol Plants. [Internet] [Thesis]. University of Wisconsin – Milwaukee; 2015. [cited 2021 Apr 15]. Available from: https://dc.uwm.edu/etd/1085.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Tamvada S. Modeling the Feasibility of Corn Stover Combustion as a Heat Source at Corn Ethanol Plants. [Thesis]. University of Wisconsin – Milwaukee; 2015. Available from: https://dc.uwm.edu/etd/1085

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

New Jersey Institute of Technology

26. Auzmendi Murua, Itsaso. Reaction mechanisms of hydrocarbon and mercury systems in the atmosphere and in combustion: A theoretical study of thermochemical and kinetic properties.

Degree: PhD, Chemical, Biological and Pharmaceutical Engineering, 2013, New Jersey Institute of Technology

URL: https://digitalcommons.njit.edu/dissertations/357

► The continuing increase in the world population and the rapidly changing lifestyle and education of this population projects significant increases in energy requirements. Global… (more)

▼ The continuing increase in the world population and the rapidly changing lifestyle and education of this population projects significant increases in energy requirements. Global warming is a worldwide major concern with a very serious potential stress on our climate threatening major changes to the environment. It is, without question, of major importance to improve the efficiency and optimize the current available combustion processes and fuel sources, to develop alternative fuels and to reduce the emissions of toxic pollutants. The objective of this dissertation is to present thermochemical, kinetic and modeling results on two reference fuels (the land vehicle fuel isooctane and the jet fuel JP-10), on smaller cyclic alkanes and ethers, and on the oxidation of mercury by the addition of halogens, in atmospheric and combustion environments. As illustrated in the combustion models developed, a fundamental understanding of the processes can enable optimization, and lead to reductions in pollutant emissions. Molecular geometries, vibration frequencies, internal rotor potentials and thermochemical properties (ΔfHº₂₉₈, S°(T) and CO_p(T)) are presented at different ab-initio, density functional theory (DFT) and composite calculation methods, with the use of several basis sets. Kinetic parameters are determined versus pressure and temperature for the chemically activated formation and unimolecular dissociation of the adducts, calculated via the use of multi-frequency quantum RRK analysis for the energy dependent rate constant with Master Equation analysis for fall off. The simulations for the determination of the important reaction paths, identification of main products and determination of combustion characteristics at different process conditions are evaluated. The thermochemical and kinetic properties developed during this work will aid in the optimization of the hydrocarbon fueled engine performance and other applications of the target fuels isooctane and JP-10. Thermochemical properties are developed for use in kinetics on oxidation and unimolecular dissociation of small cyclic alkanes and ethers for use in atmospheric and in combustion reaction mechanisms. Separately the understanding and developed kinetic and thermochemical parameters for mercury halides, and oxyhalides and the interactions of Hg and halides with NOx and SOx will help lead to a reduction of mercury emissions from power generating plants. Advisors/Committee Members: Joseph W. Bozzelli, Xianqin Wang, Robert Benedict Barat.

Subjects/Keywords: Thermochemistry; Combustion modeling; Mercury oxidation; Kinetics; Hydrocarbon oxidation; Halogens; Chemical Engineering

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APA (6^th Edition):

Auzmendi Murua, I. (2013). Reaction mechanisms of hydrocarbon and mercury systems in the atmosphere and in combustion: A theoretical study of thermochemical and kinetic properties. (Doctoral Dissertation). New Jersey Institute of Technology. Retrieved from https://digitalcommons.njit.edu/dissertations/357

Chicago Manual of Style (16^th Edition):

Auzmendi Murua, Itsaso. “Reaction mechanisms of hydrocarbon and mercury systems in the atmosphere and in combustion: A theoretical study of thermochemical and kinetic properties.” 2013. Doctoral Dissertation, New Jersey Institute of Technology. Accessed April 15, 2021. https://digitalcommons.njit.edu/dissertations/357.

MLA Handbook (7^th Edition):

Auzmendi Murua, Itsaso. “Reaction mechanisms of hydrocarbon and mercury systems in the atmosphere and in combustion: A theoretical study of thermochemical and kinetic properties.” 2013. Web. 15 Apr 2021.

Vancouver:

Auzmendi Murua I. Reaction mechanisms of hydrocarbon and mercury systems in the atmosphere and in combustion: A theoretical study of thermochemical and kinetic properties. [Internet] [Doctoral dissertation]. New Jersey Institute of Technology; 2013. [cited 2021 Apr 15]. Available from: https://digitalcommons.njit.edu/dissertations/357.

Council of Science Editors:

Auzmendi Murua I. Reaction mechanisms of hydrocarbon and mercury systems in the atmosphere and in combustion: A theoretical study of thermochemical and kinetic properties. [Doctoral Dissertation]. New Jersey Institute of Technology; 2013. Available from: https://digitalcommons.njit.edu/dissertations/357

University of Colorado

27. Nigam, Siddharth Prashant. Large Eddy Simulations of Industrial Burners.

Degree: MS, 2018, University of Colorado

URL: https://scholar.colorado.edu/mcen_gradetds/164

► During the past four years, a gift from 3M has funded a project that is at the intersection of academia and industry at the… (more)

Subjects/Keywords: burner; les; modeling; turbulence; combustion; Engineering; Mechanical Engineering

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APA (6^th Edition):

Nigam, S. P. (2018). Large Eddy Simulations of Industrial Burners. (Masters Thesis). University of Colorado. Retrieved from https://scholar.colorado.edu/mcen_gradetds/164

Chicago Manual of Style (16^th Edition):

Nigam, Siddharth Prashant. “Large Eddy Simulations of Industrial Burners.” 2018. Masters Thesis, University of Colorado. Accessed April 15, 2021. https://scholar.colorado.edu/mcen_gradetds/164.

MLA Handbook (7^th Edition):

Nigam, Siddharth Prashant. “Large Eddy Simulations of Industrial Burners.” 2018. Web. 15 Apr 2021.

Vancouver:

Nigam SP. Large Eddy Simulations of Industrial Burners. [Internet] [Masters thesis]. University of Colorado; 2018. [cited 2021 Apr 15]. Available from: https://scholar.colorado.edu/mcen_gradetds/164.

Council of Science Editors:

Nigam SP. Large Eddy Simulations of Industrial Burners. [Masters Thesis]. University of Colorado; 2018. Available from: https://scholar.colorado.edu/mcen_gradetds/164

University of Oxford

28. Fussey, Peter Michael. Automotive combustion modelling and control.

Degree: PhD, 2014, University of Oxford

URL: http://ora.ox.ac.uk/objects/uuid:ec66cbb1-407e-431c-bd77-e67bcf33be3a ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.647584

► This thesis seeks to bring together advances in control theory, modelling and controller hardware and apply them to automotive powertrains. Automotive powertrain control is dominated… (more)

Subjects/Keywords: 629.8; Control engineering; Mathematical modeling (engineering); automotive; combustion; modelling; control; diesel

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APA (6^th Edition):

Fussey, P. M. (2014). Automotive combustion modelling and control. (Doctoral Dissertation). University of Oxford. Retrieved from http://ora.ox.ac.uk/objects/uuid:ec66cbb1-407e-431c-bd77-e67bcf33be3a ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.647584

Chicago Manual of Style (16^th Edition):

Fussey, Peter Michael. “Automotive combustion modelling and control.” 2014. Doctoral Dissertation, University of Oxford. Accessed April 15, 2021. http://ora.ox.ac.uk/objects/uuid:ec66cbb1-407e-431c-bd77-e67bcf33be3a ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.647584.

MLA Handbook (7^th Edition):

Fussey, Peter Michael. “Automotive combustion modelling and control.” 2014. Web. 15 Apr 2021.

Vancouver:

Fussey PM. Automotive combustion modelling and control. [Internet] [Doctoral dissertation]. University of Oxford; 2014. [cited 2021 Apr 15]. Available from: http://ora.ox.ac.uk/objects/uuid:ec66cbb1-407e-431c-bd77-e67bcf33be3a ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.647584.

Council of Science Editors:

Fussey PM. Automotive combustion modelling and control. [Doctoral Dissertation]. University of Oxford; 2014. Available from: http://ora.ox.ac.uk/objects/uuid:ec66cbb1-407e-431c-bd77-e67bcf33be3a ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.647584

Princeton University

29. MacArt, Jonathan Francis. Computational Simulation and Modeling of Heat Release Effects on Turbulence in Turbulent Reacting Flow .

Degree: PhD, 2018, Princeton University

URL: http://arks.princeton.edu/ark:/88435/dsp015425kd39x

► This dissertation concerns the analysis and modeling of turbulence dynamics in turbulent combustion. In certain regimes of turbulent combustion, dilatation (volumetric expansion) induced by chemical… (more)

▼ This dissertation concerns the analysis and modeling of turbulence dynamics in turbulent combustion. In certain regimes of turbulent combustion, dilatation (volumetric expansion) induced by chemical heat release can result in significant modification of turbulence dynamics, leading to the failure of most common turbulence models used in predictive simulations. In this dissertation, the physical mechanisms of interaction between chemical heat release and turbulence are analyzed, scaling theories for the regime dependence of these effects are confirmed, and new turbulence models are introduced to account for these interactions. Numerical simulation forms the foundation of the analyses in this dissertation. Using a common planar jet configuration, a range of turbulent combustion regimes is accessed via Direct Numerical Simulation (DNS). In order to conduct these simulations accurately and efficiently on large-scale parallel computers, advanced numerical algorithms are introduced. These schemes improve the accuracy of state-of-the-art schemes and reduce the computational cost by approximately a factor of two. In nonpremixed combustion, heat release effects on turbulence are observed at low turbulent Reynolds number (the ratio of inertial forces to viscous forces), but the impact on turbulence model validity is minimal due to the greatly reduced turbulence intensity. In premixed combustion, scaling theories for the dependence of dilatation effects on Karlovitz number (the ratio of the flame time scale to the Kolmogorov time scale) are confirmed for the first time in turbulent shear flows. Algebraic combinations of limit-state turbulence models are proposed to account for counter-gradient transport in low Karlovitz number premixed combustion. A variable "efficiency function" controls the regime dependence of counter-gradient effects, and these models are verified a priori using the DNS databases. The algebraic approach successfully captures counter-gradient transport in the flame-normal direction, but the linear nature of these models precludes them from capturing other effects of heat release including effects of instantaneous flame motion. Finally, a new statistical description of turbulence is introduced by conditioning on an independent flame coordinate. Turbulence statistics obtained in this framework explicitly account for effects of flame motion and chemical heat release. Budgets of conditional mean velocity and turbulent kinetic energy are computed, and modeling implications are discussed. Advisors/Committee Members: Mueller, Michael E (advisor).

Subjects/Keywords: Conditional statistics; Direct Numerical Simulation; Numerical analysis; Turbulence modeling; Turbulent combustion

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

APA (6^th Edition):

MacArt, J. F. (2018). Computational Simulation and Modeling of Heat Release Effects on Turbulence in Turbulent Reacting Flow . (Doctoral Dissertation). Princeton University. Retrieved from http://arks.princeton.edu/ark:/88435/dsp015425kd39x

Chicago Manual of Style (16^th Edition):

MacArt, Jonathan Francis. “Computational Simulation and Modeling of Heat Release Effects on Turbulence in Turbulent Reacting Flow .” 2018. Doctoral Dissertation, Princeton University. Accessed April 15, 2021. http://arks.princeton.edu/ark:/88435/dsp015425kd39x.

MLA Handbook (7^th Edition):

MacArt, Jonathan Francis. “Computational Simulation and Modeling of Heat Release Effects on Turbulence in Turbulent Reacting Flow .” 2018. Web. 15 Apr 2021.

Vancouver:

MacArt JF. Computational Simulation and Modeling of Heat Release Effects on Turbulence in Turbulent Reacting Flow . [Internet] [Doctoral dissertation]. Princeton University; 2018. [cited 2021 Apr 15]. Available from: http://arks.princeton.edu/ark:/88435/dsp015425kd39x.

Council of Science Editors:

MacArt JF. Computational Simulation and Modeling of Heat Release Effects on Turbulence in Turbulent Reacting Flow . [Doctoral Dissertation]. Princeton University; 2018. Available from: http://arks.princeton.edu/ark:/88435/dsp015425kd39x

Michigan Technological University

30. Saigaonkar, Hrishikesh Abhay. AN INVESTIGATION OF VARIABLE VALVE TIMING EFFECTS ON HCCI ENGINE PERFORMANCE.

Degree: MS, Department of Mechanical Engineering-Engineering Mechanics, 2014, Michigan Technological University

URL: https://digitalcommons.mtu.edu/etds/835

► The Homogeneous Charge Compression Ignition (HCCI) engine is a promising combustion concept for reducing NO_x and particulate matter (PM) emissions and providing a high… (more)

▼ The Homogeneous Charge Compression Ignition (HCCI) engine is a promising combustion concept for reducing NO_x and particulate matter (PM) emissions and providing a high thermal efficiency in internal combustion engines. This concept though has limitations in the areas of combustion control and achieving stable combustion at high loads. For HCCI to be a viable option for on-road vehicles, further understanding of its combustion phenomenon and its control are essential. Thus, this thesis has a focus on both the experimental setup of an HCCI engine at Michigan Technological University (MTU) and also developing a physical numerical simulation model called the Sequential Model for Residual Affected HCCI (SMRH) to investigate performance of HCCI engines. The primary focus is on understanding the effects of intake and exhaust valve timings on HCCI combustion. For the experimental studies, this thesis provided the contributions for development of HCCI setup at MTU. In particular, this thesis made contributions in the areas of measurement of valve profiles, measurement of piston to valve contact clearance for procuring new pistons for further studies of high geometric compression ratio HCCI engines. It also consists of developing and testing a supercharging station and the setup of an electrical air heater to extend the HCCI operating region. The HCCI engine setup is based on a GM 2.0 L LHU Gen 1 engine which is a direct injected engine with variable valve timing (VVT) capabilities. For the simulation studies, a computationally efficient modeling platform has been developed and validated against experimental data from a single cylinder HCCI engine. In-cylinder pressure trace, combustion phasing (CA10, CA50, BD) and performance metrics IMEP, thermal efficiency, and CO emission are found to be in good agreement with experimental data for different operating conditions. Effects of phasing intake and exhaust valves are analyzed using SMRH. In addition, a novel index called Fuel Efficiency and Emissions (FEE) index is defined and is used to determine the optimal valve timings for engine operation through the use of FEE contour maps. Advisors/Committee Members: Mahdi Shahbakhti.

Subjects/Keywords: Combustion; Engines; HCCI; Sequential Modeling; WT; Mechanical Engineering

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

APA (6^th Edition):

Saigaonkar, H. A. (2014). AN INVESTIGATION OF VARIABLE VALVE TIMING EFFECTS ON HCCI ENGINE PERFORMANCE. (Masters Thesis). Michigan Technological University. Retrieved from https://digitalcommons.mtu.edu/etds/835

Chicago Manual of Style (16^th Edition):

Saigaonkar, Hrishikesh Abhay. “AN INVESTIGATION OF VARIABLE VALVE TIMING EFFECTS ON HCCI ENGINE PERFORMANCE.” 2014. Masters Thesis, Michigan Technological University. Accessed April 15, 2021. https://digitalcommons.mtu.edu/etds/835.

MLA Handbook (7^th Edition):

Saigaonkar, Hrishikesh Abhay. “AN INVESTIGATION OF VARIABLE VALVE TIMING EFFECTS ON HCCI ENGINE PERFORMANCE.” 2014. Web. 15 Apr 2021.

Vancouver:

Saigaonkar HA. AN INVESTIGATION OF VARIABLE VALVE TIMING EFFECTS ON HCCI ENGINE PERFORMANCE. [Internet] [Masters thesis]. Michigan Technological University; 2014. [cited 2021 Apr 15]. Available from: https://digitalcommons.mtu.edu/etds/835.

Council of Science Editors:

Saigaonkar HA. AN INVESTIGATION OF VARIABLE VALVE TIMING EFFECTS ON HCCI ENGINE PERFORMANCE. [Masters Thesis]. Michigan Technological University; 2014. Available from: https://digitalcommons.mtu.edu/etds/835

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