subject:(Numerical combustion)

University of Cambridge

1. Kolla, Hemanth. Scalar dissipation rate based flamelet modelling of turbulent premixed flames.

Degree: PhD, 2010, University of Cambridge

URL: http://www.dspace.cam.ac.uk/handle/1810/226254https://www.repository.cam.ac.uk/bitstream/1810/226254/2/license.txt ; https://www.repository.cam.ac.uk/bitstream/1810/226254/5/Kolla_thesis.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/226254/3/Kolla_thesis.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/226254/3/Kolla_thesis.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/226254/6/Kolla_thesis.pdf.jpg

► Lean premixed combustion has potential for reducing emissions from combustion devices without compromising fuel efficiency, but it is prone to instabilities which presents design difficulties.… (more)

▼ Lean premixed combustion has potential for reducing emissions from combustion devices without compromising fuel efficiency, but it is prone to instabilities which presents design difficulties. From emissions point of view reliable predictions of species formation rates in the flame zone are required while from the point of view of thermo – acoustics the prediction of spatial variation of heat release rate is crucial; both tasks are challenging but imperative in CFD based design of combustion systems. In this thesis a computational model for turbulent premixed combustion is proposed in the RANS framework and its predictive ability is studied. The model is based on the flamelet concept and employs strained laminar flamelets in reactant – to – product opposed flow configuration. The flamelets are parametrised by scalar dissipation rate of progress variable which is a suitable quantity to describe the flamelet structure since it is governed by convection – diffusion – reaction balance and represents the flame front dynamics. This paramaterisation is new. The mean reaction rate and mean species concentrations are obtained by integrating the corresponding flamelets quantity weighted by the joint pdf of the progress variable and its dissipation rate. The marginal pdf of the progress variable is obtained using β – pdf and the pdf of the conditional dissipation rate is presumed to be log – normal. The conditional mean dissipation rate is obtained from unconditional mean dissipation rate which is a modelling parameter. An algebraic model for the unconditional mean scalar dissipation rate is proposed based on the relevant physics of reactive scalar mixing in turbulent premixed flames. This algebraic model is validated directly using DNS data. An indirect validation is performed by deriving a turbulent flame speed expression using the Kolmogorov – Petrovskii – Piskunov analysis and comparing its predictions with experimental data from a wide range of flame and flow conditions. The mean reaction rate closure of the strained flamelets model is assessed using RANS calculations of statistically planar one – dimensional flames in corrugated flamelets and thin reaction zones regimes. The flame speeds predicted by this closure were close to experimental data in both the regimes. On the other hand, an unstrained flamelets closure predicts flame speed close to the experimental data in the corrugated flamelets regime, but overpredicts in the thin reaction zones regime indicating an overprediction of the mean reaction rate. The overall predictive ability of the strained flamelets model is assessed via calculations of laboratory flames of two different configurations: a rod stabilised V – flame and pilot stabilised Bunsen flames. For the V – flame, whose conditions correspond to the corrugated flamelets regime, the strained and unstrained flamelets models yield similar predictions which are in good agreement with experimental measurements. For the Bunsen flames which are in the thin reaction zones regime, the unstrained flamelet model…

Subjects/Keywords: Turbulent premixed combustion; Numerical modelling

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APA (6^th Edition):

Kolla, H. (2010). Scalar dissipation rate based flamelet modelling of turbulent premixed flames. (Doctoral Dissertation). University of Cambridge. Retrieved from http://www.dspace.cam.ac.uk/handle/1810/226254https://www.repository.cam.ac.uk/bitstream/1810/226254/2/license.txt ; https://www.repository.cam.ac.uk/bitstream/1810/226254/5/Kolla_thesis.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/226254/3/Kolla_thesis.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/226254/3/Kolla_thesis.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/226254/6/Kolla_thesis.pdf.jpg

Chicago Manual of Style (16^th Edition):

Kolla, Hemanth. “Scalar dissipation rate based flamelet modelling of turbulent premixed flames.” 2010. Doctoral Dissertation, University of Cambridge. Accessed March 05, 2021. http://www.dspace.cam.ac.uk/handle/1810/226254https://www.repository.cam.ac.uk/bitstream/1810/226254/2/license.txt ; https://www.repository.cam.ac.uk/bitstream/1810/226254/5/Kolla_thesis.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/226254/3/Kolla_thesis.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/226254/3/Kolla_thesis.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/226254/6/Kolla_thesis.pdf.jpg.

MLA Handbook (7^th Edition):

Kolla, Hemanth. “Scalar dissipation rate based flamelet modelling of turbulent premixed flames.” 2010. Web. 05 Mar 2021.

Vancouver:

Kolla H. Scalar dissipation rate based flamelet modelling of turbulent premixed flames. [Internet] [Doctoral dissertation]. University of Cambridge; 2010. [cited 2021 Mar 05]. Available from: http://www.dspace.cam.ac.uk/handle/1810/226254https://www.repository.cam.ac.uk/bitstream/1810/226254/2/license.txt ; https://www.repository.cam.ac.uk/bitstream/1810/226254/5/Kolla_thesis.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/226254/3/Kolla_thesis.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/226254/3/Kolla_thesis.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/226254/6/Kolla_thesis.pdf.jpg.

Council of Science Editors:

Kolla H. Scalar dissipation rate based flamelet modelling of turbulent premixed flames. [Doctoral Dissertation]. University of Cambridge; 2010. Available from: http://www.dspace.cam.ac.uk/handle/1810/226254https://www.repository.cam.ac.uk/bitstream/1810/226254/2/license.txt ; https://www.repository.cam.ac.uk/bitstream/1810/226254/5/Kolla_thesis.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/226254/3/Kolla_thesis.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/226254/3/Kolla_thesis.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/226254/6/Kolla_thesis.pdf.jpg

University of Ottawa

2. Maxwell, Brian McNeilly. Turbulent Combustion Modelling of Fast-Flames and Detonations Using Compressible LEM-LES .

Degree: 2016, University of Ottawa

URL: http://hdl.handle.net/10393/34122

► A novel approach to modelling highly compressible and reactive flows is formulated to provide high resolution closure of turbulent-scale reaction rates in the presence of… (more)

Subjects/Keywords: compressible flow; turbulent combustion; explosions; numerical simulation

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APA (6^th Edition):

Maxwell, B. M. (2016). Turbulent Combustion Modelling of Fast-Flames and Detonations Using Compressible LEM-LES . (Thesis). University of Ottawa. Retrieved from http://hdl.handle.net/10393/34122

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):

Maxwell, Brian McNeilly. “Turbulent Combustion Modelling of Fast-Flames and Detonations Using Compressible LEM-LES .” 2016. Thesis, University of Ottawa. Accessed March 05, 2021. http://hdl.handle.net/10393/34122.

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

MLA Handbook (7^th Edition):

Maxwell, Brian McNeilly. “Turbulent Combustion Modelling of Fast-Flames and Detonations Using Compressible LEM-LES .” 2016. Web. 05 Mar 2021.

Vancouver:

Maxwell BM. Turbulent Combustion Modelling of Fast-Flames and Detonations Using Compressible LEM-LES . [Internet] [Thesis]. University of Ottawa; 2016. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/10393/34122.

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

Council of Science Editors:

Maxwell BM. Turbulent Combustion Modelling of Fast-Flames and Detonations Using Compressible LEM-LES . [Thesis]. University of Ottawa; 2016. Available from: http://hdl.handle.net/10393/34122

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

University of Sydney

3. Zhao, Long Fei. Sparse-Lagrangian Multiple Mapping Conditioning Modelling of Turbulent Solid Fuel Combustion .

Degree: 2018, University of Sydney

URL: http://hdl.handle.net/2123/19658

► The focus of this thesis is to develop and implement a two-phase sparse-Lagrangian multiple mapping conditioning model for the prediction of turbulent combustion of solid… (more)

▼ The focus of this thesis is to develop and implement a two-phase sparse-Lagrangian multiple mapping conditioning model for the prediction of turbulent combustion of solid fuel. In the present day, solid fuel combustion is still a very popular method of extracting energy from fossil fuels or biomass, primarily for electricity production. Advanced numerical methods, with high fidelity combustion models, are needed in the study of the turbulent combustion of solid fuel, therefore, the model described in this thesis is dedicated to pushing the research study further in this direction. The model has three main components with two-way coupling models connecting them. A filtered reference mixture fraction is added to the Large Eddy Simulation balance equations, connecting the LES model with the other two main components developed in this study. The Sparse-Lagrangian Filtered Density Function (FDF) model provides statistical tracking of the subgrid scale variations of reactive species through a sparse set of stochastic particles. Large-scale transport properties are taken from the LES field and the gas production due to the dispersed phase devolatilisation is considered via a set of source terms added to the stochastic differential equations. A Lagrangian fuel particle (LFP) model is developed as the third model block encapsulating the predictions of solid fuel dispersion and devolatilisation, through a stochastic Lagrangian representation of the number density function (NDF). A conserved scalar driven simultaneous heat and mass transfer (SHMT) model is derived for the diffusive layer of individual fuel particles, alongside a stochastic-particle-to-fuel-particle coupling scheme to describe the exchange of species and energy between the two particles. Sensitivities to the LES grid resolutions and MMC stochastic particle resolutions are analysed with the baseline model configuration featuring Single First Order Reaction model for pyrolysis rate and pure methane for the volatile gas. The velocity and reactive scalars are generally converged at the medium and high LES resolutions, while the coarse grid show some discrepancies in capturing the turbulence-chemistry-multiphase interactions. The three sets of stochastic particle resolutions employed in the study show very consistent predictions of the mixture fraction and temperature mean conditioned on mixture fractions. The unconditional temperature mean shows some slight discrepancies towards the end of the domain. Sensitivities to the LFP model configurations are analysed through a series of baseline model upgrades, including the model for pyrolysis rate, volatile composition, and envelope flame model. The two competing rates (2CR) model with different coefficient sets is utilised as an upgrade for the SFOR model. The predictions in coal and gas temperature, as well as the rate of pyrolysis show considerable sensitivity to, both the model for pyrolysis rate and volatile composition. The current envelope flame model seems to produce some differences in instantaneous…

Subjects/Keywords: turbulent; combustion; multiphase; mmc; numerical modelling

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

APA (6^th Edition):

Zhao, L. F. (2018). Sparse-Lagrangian Multiple Mapping Conditioning Modelling of Turbulent Solid Fuel Combustion . (Thesis). University of Sydney. Retrieved from http://hdl.handle.net/2123/19658

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):

Zhao, Long Fei. “Sparse-Lagrangian Multiple Mapping Conditioning Modelling of Turbulent Solid Fuel Combustion .” 2018. Thesis, University of Sydney. Accessed March 05, 2021. http://hdl.handle.net/2123/19658.

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

MLA Handbook (7^th Edition):

Zhao, Long Fei. “Sparse-Lagrangian Multiple Mapping Conditioning Modelling of Turbulent Solid Fuel Combustion .” 2018. Web. 05 Mar 2021.

Vancouver:

Zhao LF. Sparse-Lagrangian Multiple Mapping Conditioning Modelling of Turbulent Solid Fuel Combustion . [Internet] [Thesis]. University of Sydney; 2018. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/2123/19658.

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

Council of Science Editors:

Zhao LF. Sparse-Lagrangian Multiple Mapping Conditioning Modelling of Turbulent Solid Fuel Combustion . [Thesis]. University of Sydney; 2018. Available from: http://hdl.handle.net/2123/19658

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

Princeton University

4. 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 (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 March 05, 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. 05 Mar 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 Mar 05]. 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

5. Cuif Sjöstrand, Marianne. Simulations Numériques Directes d’une méso-chambre de combustion : Mise en oeuvre et analyses : Direct Numerical simulations of a meso-scale combustion chamber : Implementation and Analysis.

Degree: Docteur es, Energétique, 2012, Rouen, INSA

URL: http://www.theses.fr/2012ISAM0022

►

La méso-combustion est le régime de combustion où la taille caractéristique du domaine est juste supérieure à la distance de coincement de la flamme ,… (more)

Subjects/Keywords: DNS; Méso-combustion; Combustion; Condition frontière; Chimie stratifiée; MEMS; Meso-combustion; Combustion chamber; Direct numerical simulations; Reactive flow; 532

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APA (6^th Edition):

Cuif Sjöstrand, M. (2012). Simulations Numériques Directes d’une méso-chambre de combustion : Mise en oeuvre et analyses : Direct Numerical simulations of a meso-scale combustion chamber : Implementation and Analysis. (Doctoral Dissertation). Rouen, INSA. Retrieved from http://www.theses.fr/2012ISAM0022

Chicago Manual of Style (16^th Edition):

Cuif Sjöstrand, Marianne. “Simulations Numériques Directes d’une méso-chambre de combustion : Mise en oeuvre et analyses : Direct Numerical simulations of a meso-scale combustion chamber : Implementation and Analysis.” 2012. Doctoral Dissertation, Rouen, INSA. Accessed March 05, 2021. http://www.theses.fr/2012ISAM0022.

MLA Handbook (7^th Edition):

Cuif Sjöstrand, Marianne. “Simulations Numériques Directes d’une méso-chambre de combustion : Mise en oeuvre et analyses : Direct Numerical simulations of a meso-scale combustion chamber : Implementation and Analysis.” 2012. Web. 05 Mar 2021.

Vancouver:

Cuif Sjöstrand M. Simulations Numériques Directes d’une méso-chambre de combustion : Mise en oeuvre et analyses : Direct Numerical simulations of a meso-scale combustion chamber : Implementation and Analysis. [Internet] [Doctoral dissertation]. Rouen, INSA; 2012. [cited 2021 Mar 05]. Available from: http://www.theses.fr/2012ISAM0022.

Council of Science Editors:

Cuif Sjöstrand M. Simulations Numériques Directes d’une méso-chambre de combustion : Mise en oeuvre et analyses : Direct Numerical simulations of a meso-scale combustion chamber : Implementation and Analysis. [Doctoral Dissertation]. Rouen, INSA; 2012. Available from: http://www.theses.fr/2012ISAM0022

6. Jaouen, Nicolas. An automated approach to derive and optimise reduced chemical mechanisms for turbulent combustion : Une approche automatisée pour la réduction et l'optimisation de schémas cinétiques appliqués à la combustion turbulente.

Degree: Docteur es, Energétique, 2017, Normandie

URL: http://www.theses.fr/2017NORMIR03

►

La complexité de la chimie joue un rôle majeur dans la simulation numérique de la plupart des écoulements réactifs industriels. L'utilisation de schémas cinétiques chimiques… (more)

▼

La complexité de la chimie joue un rôle majeur dans la simulation numérique de la plupart des écoulements réactifs industriels. L'utilisation de schémas cinétiques chimiques détaillés avec les outils de simulation actuels reste toutefois trop coûteuse du fait des faibles pas de temps et d'espaces associés à la résolution d'une flamme, bien souvent inférieurs de plusieurs ordres de grandeur à ceux nécessaires pour capturer les effets de la turbulence. Une solution est proposée pour s'affranchir de cette limite. Un outil automatisé de réduction de schémas cinétiques est développé sur la base d'un ensemble de trajectoires de références construites dans l'espace des compositions pour être représentatives du système à simuler. Ces trajectoires sont calculées à partir de l'évolution de particules stochastiques soumises à différentes conditions de mélange, de réaction et d'évaporation dans le cas de combustible liquide. L'ensemble est couplé à un algorithme génétique pour l'optimisation des taux de réaction du schéma réduit, permettant ainsi une forte réduction du coût calcul. L'approche a été validée et utilisée pour la réduction de divers mécanismes réactionnels sur des applications académiques et industrielles, pour des hydrocarbures simples comme le méthane jusqu'à des hydrocarbures plus complexes, comme le kérosène en incluant une étape optimisée de regroupement des isomères.

Complex chemistry is an essential ingredient in advanced numerical simulation of combustion systems. However, introducing detailed chemistry in Computational Fluid Dynamics (CFD) softwares is a non trivial task since the time and space resolutions necessary to capture and solve for a flame are very often smaller than the turbulent characteristic scales by several orders of magnitude. A solution based on the reduction of chemical mechanisms is proposed to tackle this issue. An automated reduction and optimisation strategy is suggested relying on the construction of reference trajectories computed with the evolution of stochastic particles that face mixing, evaporation and chemical reactions. The methodology, which offers strong reduction in CPU cost, is applied to the derivation of several mechanisms for canonical and industrial applications, for simple fuel such as methane up to more complex hydrocarbon fuels, as kerosene, including an optimised lumping procedure for isomers.

Advisors/Committee Members: Domingo, Pascale (thesis director), Vervisch, Luc (thesis director).

Subjects/Keywords: Chimie réduite; Simulation numérique; Combustion turbulente; Reduced chemistry; Genetic algorithm; Numerical simulation; Turbulent combustion

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

APA (6^th Edition):

Jaouen, N. (2017). An automated approach to derive and optimise reduced chemical mechanisms for turbulent combustion : Une approche automatisée pour la réduction et l'optimisation de schémas cinétiques appliqués à la combustion turbulente. (Doctoral Dissertation). Normandie. Retrieved from http://www.theses.fr/2017NORMIR03

Chicago Manual of Style (16^th Edition):

Jaouen, Nicolas. “An automated approach to derive and optimise reduced chemical mechanisms for turbulent combustion : Une approche automatisée pour la réduction et l'optimisation de schémas cinétiques appliqués à la combustion turbulente.” 2017. Doctoral Dissertation, Normandie. Accessed March 05, 2021. http://www.theses.fr/2017NORMIR03.

MLA Handbook (7^th Edition):

Jaouen, Nicolas. “An automated approach to derive and optimise reduced chemical mechanisms for turbulent combustion : Une approche automatisée pour la réduction et l'optimisation de schémas cinétiques appliqués à la combustion turbulente.” 2017. Web. 05 Mar 2021.

Vancouver:

Jaouen N. An automated approach to derive and optimise reduced chemical mechanisms for turbulent combustion : Une approche automatisée pour la réduction et l'optimisation de schémas cinétiques appliqués à la combustion turbulente. [Internet] [Doctoral dissertation]. Normandie; 2017. [cited 2021 Mar 05]. Available from: http://www.theses.fr/2017NORMIR03.

Council of Science Editors:

Jaouen N. An automated approach to derive and optimise reduced chemical mechanisms for turbulent combustion : Une approche automatisée pour la réduction et l'optimisation de schémas cinétiques appliqués à la combustion turbulente. [Doctoral Dissertation]. Normandie; 2017. Available from: http://www.theses.fr/2017NORMIR03

INP Toulouse

7. Dupuy, Fabien. Reduced Order Models and Large Eddy Simulation for Combustion Instabilities in aeronautical Gas Turbines : Modèles réduits et Simulations aux Grandes Echelles pour les instabilités thermoacoustiques dans les turbines à gaz aéronautiques.

Degree: Docteur es, Energétique et Transferts, 2020, INP Toulouse

URL: http://www.theses.fr/2020INPT0046

► Des réglementations de plus en plus strictes et un intérêt environnemental grandissant ont poussé les constructeurs de moteurs aéronautiques à développer la génération actuelle de… (more)

▼ Des réglementations de plus en plus strictes et un intérêt environnemental grandissant ont poussé les constructeurs de moteurs aéronautiques à développer la génération actuelle de chambres de combustion, affichant des consommations et émissions de polluants plus basses que jamais. Cependant, les phases de conception de chambres modernes ont clairement mis en évidence que celles-ci sont plus susceptibles de développer des instabilités de combustion, où le couplage entre l'acoustique de la chambre et la flamme suscite de larges oscillations de pression ainsi que des vibrations de la structure. Ces instabilités peuvent endommager le moteur, et potentiellement entraîner sa destruction. Dans le même temps, de considérables avancées ont eu lieu dans le domaine de la simulation numérique, et la Mécanique des Fluides Numérique (MFN) a démontré sa capacité à reproduire la dynamique de flammes instationnaires et les instabilités de combustion observées dans les moteurs. Pourtant, même avec le matériel informatique moderne, le temps de calcul reste la contrainte clé de ces simulations haute-fidélité, qui demeurent très coûteuses. Typiquement, couvrir la totalité du domaine de fonctionnement pour un moteur industriel est encore hors de portée. Des modèles dits bas-ordre existent également, et prédire efficacement les instabilités de combustion par leur intermédiaire est envisageable à la condition d'une modélisation appropriée de l'interaction entre l'acoustique et la flamme. La méthode de modélisation la plus commune de cet élément critique est la fonction de transfert de flamme (FTF) qui lie les fluctuations de taux de dégagement de chaleur aux fluctuations de vitesse en un point donné. Cette fonction de transfert peut être obtenue à partir de modèles analytiques, mais très peu existent pour des flammes swirlées turbulentes. Une autre approche consiste à réaliser des mesures expérimentales ou des simulations haute fidélité coûteuses, réduisant à néant la capacité de prédiction rapide recherchée avec les méthodes bas-ordre. Cette thèse vise donc à développer des outils bas ordre à la fois rapides et fiables pour la modélisation des instabilités de combustion, ainsi qu'à améliorer la compréhension des mécanismes inhérents à la réponse acoustique d'une flamme swirlée. A cet effet, une approche hybride nouvelle est proposée, où un nombre réduit de simulations haute fidélité peut être utilisé pour déterminer les paramètres d'entrée d'un modèle analytique représentatif de la fonction de transfert d'une flamme swirlée prémélangée. Le modèle analytique s'appuie sur des travaux antérieurs traitant la flamme comme une interface perturbée, et prend en compte la conversion acoustique-vorticité à travers un swirler. La validité du modèle est mise à l'épreuve en déterminant les divers paramètres nécessaires associés à partir de simulations numériques réactives stationnaires et pulsées d'une flamme prémélangée swirlée académique. Il est également démontré que le modèle peut prendre en compte diverses amplitudes de perturbation. Enfin, des… Advisors/Committee Members: Poinsot, Thierry (thesis director), Gicquel, Laurent (thesis director).

Subjects/Keywords: Combustion; Instabilités; Simulation numérique; Acoustique; Turbine à gaz; Combustion; Instabilities; Numerical simulation; Acoustics; Gas turbine

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

APA (6^th Edition):

Dupuy, F. (2020). Reduced Order Models and Large Eddy Simulation for Combustion Instabilities in aeronautical Gas Turbines : Modèles réduits et Simulations aux Grandes Echelles pour les instabilités thermoacoustiques dans les turbines à gaz aéronautiques. (Doctoral Dissertation). INP Toulouse. Retrieved from http://www.theses.fr/2020INPT0046

Chicago Manual of Style (16^th Edition):

Dupuy, Fabien. “Reduced Order Models and Large Eddy Simulation for Combustion Instabilities in aeronautical Gas Turbines : Modèles réduits et Simulations aux Grandes Echelles pour les instabilités thermoacoustiques dans les turbines à gaz aéronautiques.” 2020. Doctoral Dissertation, INP Toulouse. Accessed March 05, 2021. http://www.theses.fr/2020INPT0046.

MLA Handbook (7^th Edition):

Dupuy, Fabien. “Reduced Order Models and Large Eddy Simulation for Combustion Instabilities in aeronautical Gas Turbines : Modèles réduits et Simulations aux Grandes Echelles pour les instabilités thermoacoustiques dans les turbines à gaz aéronautiques.” 2020. Web. 05 Mar 2021.

Vancouver:

Dupuy F. Reduced Order Models and Large Eddy Simulation for Combustion Instabilities in aeronautical Gas Turbines : Modèles réduits et Simulations aux Grandes Echelles pour les instabilités thermoacoustiques dans les turbines à gaz aéronautiques. [Internet] [Doctoral dissertation]. INP Toulouse; 2020. [cited 2021 Mar 05]. Available from: http://www.theses.fr/2020INPT0046.

Council of Science Editors:

Dupuy F. Reduced Order Models and Large Eddy Simulation for Combustion Instabilities in aeronautical Gas Turbines : Modèles réduits et Simulations aux Grandes Echelles pour les instabilités thermoacoustiques dans les turbines à gaz aéronautiques. [Doctoral Dissertation]. INP Toulouse; 2020. Available from: http://www.theses.fr/2020INPT0046

8. Martínez Ferrer, Pedro José. Étude par simulation numérique de l'auto-allumage en écoulement turbulent cisaillé supersonique : Numerical simulation of self-ignition in supersonic turbulent shear flow.

Degree: Docteur es, Energétique, thermique, combustion, 2013, Chasseneuil-du-Poitou, Ecole nationale supérieure de mécanique et d'aérotechnique

URL: http://www.theses.fr/2013ESMA0018

►

Cette étude est consacrée à l’analyse des écoulements réactifs supersoniques cisailléset, plus particulièrement, des couches de mélange compressibles pouvant se développerdans les moteurs ramjet et… (more)

▼

Cette étude est consacrée à l’analyse des écoulements réactifs supersoniques cisailléset, plus particulièrement, des couches de mélange compressibles pouvant se développerdans les moteurs ramjet et scramjet. Des méthodes numériques appropriées ont été implémentéeset vérifiées pour aboutir au développement d’un code de calcul numériquemassivement parallèle, appelé CREAMS (compressible reactive multi-species solver). Cedernier a été spécialement conçu pour conduire des simulations numériques haute précision(simulations numériques directes ou DNS) de ce type d’écoulements. Une attentionparticulière a été portée à la description des termes de transport moléculaire et des termessources chimiques de façon à considérer la description physique la plus fidèle possible desmélanges des gaz réactifs à haute vitesse, au sein desquelles les temps caractéristiqueschimiques et de mélange aux petites échelles sont susceptibles d’être du même ordre degrandeur. Les simulations des couches de mélange bidimensionnelles et tridimensionnelles,inertes et réactives, confirment l’importance des effets associés à la compressibilité et autaux de dégagement de chaleur. Les résultats ainsi obtenus diffèrent en certains points deceux issus d’autres simulations qui introduisaient certaines hypothèses simplificatrices :développement temporel, emploi d’une chimie globale ou encore lois de transport simplifiées.En revanche, ils reproduisent certains tendances déjà observées dans un certainnombre d’études expérimentales conduites dans des conditions similaires.

This study is devoted to the analysis of supersonic reactive shear flows and, in particular,compressible mixing layers that can develop inside the ramjet and scramjet engines.Appropriate numerical methods have been implemented and tested to achieve the developmentof a massively parallel numerical solver, called CREAMS (compressible reactivemulti-species solver). This tool was designed to conduct high-precision numerical simulations(direct numerical simulations or DNS) of such flows. Particular attention waspaid to the description of the molecular transport terms and chemical source terms toconsider the most accurate physical description of reactive gas mixtures at high velocity,in which the chemical and mixing time scales, corresponding to the smallest scalesof the flow, are susceptible to be of the same order of magnitude. Simulations of twoandthree-dimensional, inert and reactive, mixing layers confirm the importance of theeffects associated with compressibility and rate of heat release. The results obtained differin some points from other simulations which introduced simplifying assumptions such astemporal development, use of a global chemistry or a simplified description of the moleculartransport terms. Nevertheless, they reproduce some trends already observed in severalexperimental studies conducted under similar conditions.

Advisors/Committee Members: Mura, Arnaud (thesis director), Lehnasch, Guillaume (thesis director), Sabel'Nikov, Vladimir (thesis director).

Subjects/Keywords: Couche de mélange; Combustion supersonique; SImulation numérique directe; Mixing layer; Supersonic combustion; Direct numerical simulation

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

APA (6^th Edition):

Martínez Ferrer, P. J. (2013). Étude par simulation numérique de l'auto-allumage en écoulement turbulent cisaillé supersonique : Numerical simulation of self-ignition in supersonic turbulent shear flow. (Doctoral Dissertation). Chasseneuil-du-Poitou, Ecole nationale supérieure de mécanique et d'aérotechnique. Retrieved from http://www.theses.fr/2013ESMA0018

Chicago Manual of Style (16^th Edition):

Martínez Ferrer, Pedro José. “Étude par simulation numérique de l'auto-allumage en écoulement turbulent cisaillé supersonique : Numerical simulation of self-ignition in supersonic turbulent shear flow.” 2013. Doctoral Dissertation, Chasseneuil-du-Poitou, Ecole nationale supérieure de mécanique et d'aérotechnique. Accessed March 05, 2021. http://www.theses.fr/2013ESMA0018.

MLA Handbook (7^th Edition):

Martínez Ferrer, Pedro José. “Étude par simulation numérique de l'auto-allumage en écoulement turbulent cisaillé supersonique : Numerical simulation of self-ignition in supersonic turbulent shear flow.” 2013. Web. 05 Mar 2021.

Vancouver:

Martínez Ferrer PJ. Étude par simulation numérique de l'auto-allumage en écoulement turbulent cisaillé supersonique : Numerical simulation of self-ignition in supersonic turbulent shear flow. [Internet] [Doctoral dissertation]. Chasseneuil-du-Poitou, Ecole nationale supérieure de mécanique et d'aérotechnique; 2013. [cited 2021 Mar 05]. Available from: http://www.theses.fr/2013ESMA0018.

Council of Science Editors:

Martínez Ferrer PJ. Étude par simulation numérique de l'auto-allumage en écoulement turbulent cisaillé supersonique : Numerical simulation of self-ignition in supersonic turbulent shear flow. [Doctoral Dissertation]. Chasseneuil-du-Poitou, Ecole nationale supérieure de mécanique et d'aérotechnique; 2013. Available from: http://www.theses.fr/2013ESMA0018

9. Wilson, David. Application of a Multi-Zone Model for the Prediction of Species Concentrations in Rapid Compression Machine Experiments.

Degree: 2016, Marquette University

URL: https://epublications.marquette.edu/theses_open/348

► Accurate chemical kinetic models, which predict species evolution and heat release rates in chemically reactive systems, are essential for further advancements in fuel and combustion… (more)

▼ Accurate chemical kinetic models, which predict species evolution and heat release rates in chemically reactive systems, are essential for further advancements in fuel and combustion technology. An experimental facility that is widely used for evaluating the accuracy of kinetic models is a rapid compression machine (RCM), which creates a well-defined reaction environment by compressing a reactive mixture inside a chamber. Generally, RCM experiments are conducted in order to obtain ignition delay data. However, chemical speciation data provides greater insight into reaction pathways, and is therefore a more rigorous benchmark for validating kinetic models. In order for a chemical kinetic model to be evaluated using RCM data, the kinetic model must be coupled with a thermodynamic model that can predict the temporally varying conditions that evolve during an RCM experiment. The most common approach is to utilize a thermally and compositionally homogeneous 0-dimensional reactor model (HRM), which predicts conditions inside the hot core region of the main combustion chamber of an RCM, where a significant portion of the chemical reaction in an RCM takes place. This approach requires an effective volume profile, which is derived from the pressure profile of either a non-reactive experiment with similar transport properties as the condition of interest, or a separate multi-zone model (MZM), via the relationship between pressure and volume for an isentropic process. While HRMs have been shown to yield adequate ignition delay predictions, they cannot be used to predict average speciation data, since the conditions in the core region vary considerably from the average conditions of the total reaction chamber. This work introduces a modified MZM, which simulates chemical reaction throughout the entire temperature-varying main combustion chamber of an RCM, in addition to boundary work, conduction, and crevice flows as the traditional MZM approach. Simulating chemistry in the MZM allows for average speciation predictions, and eliminates the need for an HRM. The new approach is shown to yield similar average speciation data as CFD simulations (within 15% difference) for the combustion of primary reference fuels at various conditions. Advisors/Committee Members: Allen, Casey M., Singer, Simcha, Borg, John.

Subjects/Keywords: Chemical Kinetics; Combustion; Numerical Model; Rapid Compression Machine; Applied Mechanics; Heat Transfer, Combustion

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

APA (6^th Edition):

Wilson, D. (2016). Application of a Multi-Zone Model for the Prediction of Species Concentrations in Rapid Compression Machine Experiments. (Thesis). Marquette University. Retrieved from https://epublications.marquette.edu/theses_open/348

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):

Wilson, David. “Application of a Multi-Zone Model for the Prediction of Species Concentrations in Rapid Compression Machine Experiments.” 2016. Thesis, Marquette University. Accessed March 05, 2021. https://epublications.marquette.edu/theses_open/348.

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

MLA Handbook (7^th Edition):

Wilson, David. “Application of a Multi-Zone Model for the Prediction of Species Concentrations in Rapid Compression Machine Experiments.” 2016. Web. 05 Mar 2021.

Vancouver:

Wilson D. Application of a Multi-Zone Model for the Prediction of Species Concentrations in Rapid Compression Machine Experiments. [Internet] [Thesis]. Marquette University; 2016. [cited 2021 Mar 05]. Available from: https://epublications.marquette.edu/theses_open/348.

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

Council of Science Editors:

Wilson D. Application of a Multi-Zone Model for the Prediction of Species Concentrations in Rapid Compression Machine Experiments. [Thesis]. Marquette University; 2016. Available from: https://epublications.marquette.edu/theses_open/348

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

King Abdullah University of Science and Technology

10. Khamedov, Ruslan. A Computational Study of Ammonia Combustion.

Degree: Physical Science and Engineering (PSE) Division, 2020, King Abdullah University of Science and Technology

URL: http://hdl.handle.net/10754/663983

► The utilization of ammonia as a fuel is a pragmatic approach to pave the way towards a low-carbon economy. Ammonia compromises almost 18 % of… (more)

▼ The utilization of ammonia as a fuel is a pragmatic approach to pave the way towards a low-carbon economy. Ammonia compromises almost 18 % of hydrogen by mass and accepted as one of the hydrogen combustion enablers with existing infrastructure for transportation and storage. From an environmental and sustainability standpoint, ammonia combustion is an attractive energy source with zero carbon dioxide emissions. However, from a practical point of view, the direct combustion of ammonia is not feasible due to the low reactive nature of ammonia. Due to the low combustion intensity, and the higher nitrogen oxide emission, ammonia was not fully investigated and there is still a lack of fundamental knowledge of ammonia combustion. In this thesis, the computational study of ammonia premixed flame characteristics under various hydrogen addition ratios and moderate or intense low oxygen dilution (MILD) conditions were investigated. Particularly, the heat release characteristics and dominant reaction pathways were analyzed. The analysis revealed that the peak of heat release for ammonia flame occurs near burned gas, which raises a question regarding the physics of this. Further analysis identified the dominant reaction pathways and the intermediate species (NH2 and OH), which are mainly produced in the downstream and back diffused to the leading edge and produce some heat in the low-temperature zone. To overcome low reactivity and poor combustion performance of pure ammonia mixture, the onboard ammonia decomposition to hydrogen and nitrogen followed by blending ammonia with hydrogen is a feasible approach to improve ammonia combustion intensity. With increasing hydrogen amount in the mixture, the enhancement of heat release occurs due to both transport and chemical effect of hydrogen. Another approach to mitigate the low reactive nature of ammonia may be eliminated by applying the promising combustion concept known as MILD combustion. The heat release characteristics and flame marker of ammonia turbulent premixed MILD combustion were investigated. The high fidelity numerical simulation was performed to answer fundamental questions of ammonia turbulent premixed combustion characteristics. Advisors/Committee Members: Im, Hong G. (advisor), Roberts, William Lafayette (committee member), Knio, Omar (committee member), Parsani, Matteo (committee member).

Subjects/Keywords: ammonia combustion; carbon-free fuel; Direct numerical simulation; heat release rate; numerical simulation; turbulent premixed combustion

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APA (6^th Edition):

Khamedov, R. (2020). A Computational Study of Ammonia Combustion. (Thesis). King Abdullah University of Science and Technology. Retrieved from http://hdl.handle.net/10754/663983

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):

Khamedov, Ruslan. “A Computational Study of Ammonia Combustion.” 2020. Thesis, King Abdullah University of Science and Technology. Accessed March 05, 2021. http://hdl.handle.net/10754/663983.

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

MLA Handbook (7^th Edition):

Khamedov, Ruslan. “A Computational Study of Ammonia Combustion.” 2020. Web. 05 Mar 2021.

Vancouver:

Khamedov R. A Computational Study of Ammonia Combustion. [Internet] [Thesis]. King Abdullah University of Science and Technology; 2020. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/10754/663983.

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

Council of Science Editors:

Khamedov R. A Computational Study of Ammonia Combustion. [Thesis]. King Abdullah University of Science and Technology; 2020. Available from: http://hdl.handle.net/10754/663983

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

University of Toronto

11. Wang, Weichao. Experimental and Numerical Investigation of Structure and Extinction Limits of Biofuels in Laminar Counterflow Diffusion Flames.

Degree: 2014, University of Toronto

URL: http://hdl.handle.net/1807/67886

►

Extinction of laminar counterflow diffusion flames were investigated at atmospheric pressures as a function of nitrogen dilution through experiment and two-dimensional axisymmetric full domain numerical… (more)

Subjects/Keywords: Ethanol combustion; Flame extinction; Laminar counterflow diffusion flames; Numerical combustion modelling; Strain rate; Syngas combustion; 0538

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

APA (6^th Edition):

Wang, W. (2014). Experimental and Numerical Investigation of Structure and Extinction Limits of Biofuels in Laminar Counterflow Diffusion Flames. (Masters Thesis). University of Toronto. Retrieved from http://hdl.handle.net/1807/67886

Chicago Manual of Style (16^th Edition):

Wang, Weichao. “Experimental and Numerical Investigation of Structure and Extinction Limits of Biofuels in Laminar Counterflow Diffusion Flames.” 2014. Masters Thesis, University of Toronto. Accessed March 05, 2021. http://hdl.handle.net/1807/67886.

MLA Handbook (7^th Edition):

Wang, Weichao. “Experimental and Numerical Investigation of Structure and Extinction Limits of Biofuels in Laminar Counterflow Diffusion Flames.” 2014. Web. 05 Mar 2021.

Vancouver:

Wang W. Experimental and Numerical Investigation of Structure and Extinction Limits of Biofuels in Laminar Counterflow Diffusion Flames. [Internet] [Masters thesis]. University of Toronto; 2014. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1807/67886.

Council of Science Editors:

Wang W. Experimental and Numerical Investigation of Structure and Extinction Limits of Biofuels in Laminar Counterflow Diffusion Flames. [Masters Thesis]. University of Toronto; 2014. Available from: http://hdl.handle.net/1807/67886

NSYSU

12. HUANG, JING-YAO. The Model Development and Numerical Simulation for Scrap Tyre Buring in the Steel Melting Process.

Degree: Master, Mechanical and Electro-Mechanical Engineering, 2015, NSYSU

URL: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0731115-111011

► In this study, a transient 3-D numerical model is built to investigate the tire burning in a furnace. In this study, the turbulence k-Îµ model… (more)

Subjects/Keywords: Numerical simulation; tire combustion; Steelmaking; hot furnace; destruction and removal efficiency

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

APA (6^th Edition):

HUANG, J. (2015). The Model Development and Numerical Simulation for Scrap Tyre Buring in the Steel Melting Process. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0731115-111011

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):

HUANG, JING-YAO. “The Model Development and Numerical Simulation for Scrap Tyre Buring in the Steel Melting Process.” 2015. Thesis, NSYSU. Accessed March 05, 2021. http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0731115-111011.

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

MLA Handbook (7^th Edition):

HUANG, JING-YAO. “The Model Development and Numerical Simulation for Scrap Tyre Buring in the Steel Melting Process.” 2015. Web. 05 Mar 2021.

Vancouver:

HUANG J. The Model Development and Numerical Simulation for Scrap Tyre Buring in the Steel Melting Process. [Internet] [Thesis]. NSYSU; 2015. [cited 2021 Mar 05]. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0731115-111011.

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

Council of Science Editors:

HUANG J. The Model Development and Numerical Simulation for Scrap Tyre Buring in the Steel Melting Process. [Thesis]. NSYSU; 2015. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0731115-111011

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

University of Toronto

13. Nijsse, Jeff. Numerical Modelling of Staged Combustion Aft-injected Hybrid Rocket Motors.

Degree: 2012, University of Toronto

URL: http://hdl.handle.net/1807/33478

►

The staged combustion aft-injected hybrid (SCAIH) rocket motor is a promising design for the future of hybrid rocket propulsion. Advances in computational fluid dynamics and… (more)

Subjects/Keywords: Computational Fluid Dynamics; Turbulent Combustion; Hybrid Rocket Motors; Numerical Modelling; 0538

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APA (6^th Edition):

Nijsse, J. (2012). Numerical Modelling of Staged Combustion Aft-injected Hybrid Rocket Motors. (Masters Thesis). University of Toronto. Retrieved from http://hdl.handle.net/1807/33478

Chicago Manual of Style (16^th Edition):

Nijsse, Jeff. “Numerical Modelling of Staged Combustion Aft-injected Hybrid Rocket Motors.” 2012. Masters Thesis, University of Toronto. Accessed March 05, 2021. http://hdl.handle.net/1807/33478.

MLA Handbook (7^th Edition):

Nijsse, Jeff. “Numerical Modelling of Staged Combustion Aft-injected Hybrid Rocket Motors.” 2012. Web. 05 Mar 2021.

Vancouver:

Nijsse J. Numerical Modelling of Staged Combustion Aft-injected Hybrid Rocket Motors. [Internet] [Masters thesis]. University of Toronto; 2012. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1807/33478.

Council of Science Editors:

Nijsse J. Numerical Modelling of Staged Combustion Aft-injected Hybrid Rocket Motors. [Masters Thesis]. University of Toronto; 2012. Available from: http://hdl.handle.net/1807/33478

University of Toronto

14. Shum, Justin. The Development and Validation of a Simplified Soot Model for use in Soot Emissions Prediction in Natural Gas Fuelled Engine Simulations.

Degree: 2012, University of Toronto

URL: http://hdl.handle.net/1807/33528

►

This study employs a novel approach in order to satisfy the need in industry for a computationally inexpensive means to modelling soot formation in engines… (more)

Subjects/Keywords: Soot; Model; Simulation; Combustion; Methane; Numerical; Nanoparticles; Laminar Flame; 0548

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

APA (6^th Edition):

Shum, J. (2012). The Development and Validation of a Simplified Soot Model for use in Soot Emissions Prediction in Natural Gas Fuelled Engine Simulations. (Masters Thesis). University of Toronto. Retrieved from http://hdl.handle.net/1807/33528

Chicago Manual of Style (16^th Edition):

Shum, Justin. “The Development and Validation of a Simplified Soot Model for use in Soot Emissions Prediction in Natural Gas Fuelled Engine Simulations.” 2012. Masters Thesis, University of Toronto. Accessed March 05, 2021. http://hdl.handle.net/1807/33528.

MLA Handbook (7^th Edition):

Shum, Justin. “The Development and Validation of a Simplified Soot Model for use in Soot Emissions Prediction in Natural Gas Fuelled Engine Simulations.” 2012. Web. 05 Mar 2021.

Vancouver:

Shum J. The Development and Validation of a Simplified Soot Model for use in Soot Emissions Prediction in Natural Gas Fuelled Engine Simulations. [Internet] [Masters thesis]. University of Toronto; 2012. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1807/33528.

Council of Science Editors:

Shum J. The Development and Validation of a Simplified Soot Model for use in Soot Emissions Prediction in Natural Gas Fuelled Engine Simulations. [Masters Thesis]. University of Toronto; 2012. Available from: http://hdl.handle.net/1807/33528

Halmstad University

15. Erling, Fredrik. Static CFD analysis of a novel valve design for internal combustion engines.

Degree: Computer and Electrical Engineering (IDE), 2011, Halmstad University

URL: http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-15521

► In this work CFD was used to simulate the flow through a novel valve design for internal combustion engines. CFD is numerical method for… (more)

Subjects/Keywords: CFD; valve; Internal Combustion Engine; Numerical analysis; Numerisk analys

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APA (6^th Edition):

Erling, F. (2011). Static CFD analysis of a novel valve design for internal combustion engines. (Thesis). Halmstad University. Retrieved from http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-15521

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):

Erling, Fredrik. “Static CFD analysis of a novel valve design for internal combustion engines.” 2011. Thesis, Halmstad University. Accessed March 05, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-15521.

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

MLA Handbook (7^th Edition):

Erling, Fredrik. “Static CFD analysis of a novel valve design for internal combustion engines.” 2011. Web. 05 Mar 2021.

Vancouver:

Erling F. Static CFD analysis of a novel valve design for internal combustion engines. [Internet] [Thesis]. Halmstad University; 2011. [cited 2021 Mar 05]. Available from: http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-15521.

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

Council of Science Editors:

Erling F. Static CFD analysis of a novel valve design for internal combustion engines. [Thesis]. Halmstad University; 2011. Available from: http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-15521

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

Delft University of Technology

16. Huijts, Melchior (author). An experimental and numerical investigation of the aerodynamic characteristics of a flameless combustor.

Degree: 2018, Delft University of Technology

URL: http://resolver.tudelft.nl/uuid:acf41200-c4f4-4004-8d24-dcc5f8d6dd7c

► NOx emissions cause harm to the human body, the world around us and our atmosphere, both directly and indirectly. Flameless combustion is a combustion regime… (more)

Subjects/Keywords: Flameless Combustion; PIV; RANS; CFD; Recirculation; Entrainment; Experimental; Numerical

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APA (6^th Edition):

Huijts, M. (. (2018). An experimental and numerical investigation of the aerodynamic characteristics of a flameless combustor. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:acf41200-c4f4-4004-8d24-dcc5f8d6dd7c

Chicago Manual of Style (16^th Edition):

Huijts, Melchior (author). “An experimental and numerical investigation of the aerodynamic characteristics of a flameless combustor.” 2018. Masters Thesis, Delft University of Technology. Accessed March 05, 2021. http://resolver.tudelft.nl/uuid:acf41200-c4f4-4004-8d24-dcc5f8d6dd7c.

MLA Handbook (7^th Edition):

Huijts, Melchior (author). “An experimental and numerical investigation of the aerodynamic characteristics of a flameless combustor.” 2018. Web. 05 Mar 2021.

Vancouver:

Huijts M(. An experimental and numerical investigation of the aerodynamic characteristics of a flameless combustor. [Internet] [Masters thesis]. Delft University of Technology; 2018. [cited 2021 Mar 05]. Available from: http://resolver.tudelft.nl/uuid:acf41200-c4f4-4004-8d24-dcc5f8d6dd7c.

Council of Science Editors:

Huijts M(. An experimental and numerical investigation of the aerodynamic characteristics of a flameless combustor. [Masters Thesis]. Delft University of Technology; 2018. Available from: http://resolver.tudelft.nl/uuid:acf41200-c4f4-4004-8d24-dcc5f8d6dd7c

University of Toronto

17. Tobaldini Neto, Luiz Tobaldini. High-order Finite-volume CENO Scheme for Large-Eddy Simulation of Premixed Flames.

Degree: PhD, 2019, University of Toronto

URL: http://hdl.handle.net/1807/97004

► A novel, parallel, high-order, central essentially non-oscillatory (CENO), cell-centered, finite-volume scheme is developed and applied to large-eddy simulation (LES) of turbulent premixed flames. The high-order… (more)

▼ A novel, parallel, high-order, central essentially non-oscillatory (CENO), cell-centered, finite-volume scheme is developed and applied to large-eddy simulation (LES) of turbulent premixed flames. The high-order CENO finite-volume scheme is applied to the solution of the Favre-filtered Navier-Stokes equations governing turbulent flows of a fully compressible reactive mixture on a three-dimensional, multi-block, body-fitted, computational mesh consisting of hexahedral volume elements. The CENO method uses a hybrid reconstruction approach based on a fixed central stencil. The discretization of the inviscid fluxes combines an unlimited high-order least-squares reconstruction technique based on the optimal central stencil with a monotonicity preserving, limited, linear, reconstruction algorithm. Switching in the hybrid procedure is determined by a smoothness indicator such that the unlimited high-order reconstruction is retained for smooth solution content that is fully resolved and reverts to the limited lower-order scheme, enforcing solution monotonicity, for regions with abrupt variations (i.e., discontinuities and under-resolved regions). The high-order viscous fluxes are computed to the same order of accuracy as the hyperbolic fluxes based on a high-order accurate cell interface gradient derived from the unlimited, cell-centered, reconstruction. The proposed cell-centered finite-volume scheme is formulated for three-dimensional multi-block mesh consisting of generic hexahedral cells and applied to LES of premixed flames. For the reactive flows of interest here, a flamelet-based subfilter-scale (SFS) model is used to describe the unresolved influences of interaction between the turbulence and combustion. This SFS combustion model is based on a presumed conditional moment (PCM) approach in conjunction with flame prolongation of intrinsic low-dimensional manifold (FPI) tabulated chemistry. Numerical results are discussed for a laboratory-scale lean premixed methane-air Bunsen-type flame. The performance of the proposed high-order scheme for turbulent reactive flows is analysed by a systematic mesh refinement study using different spatial orders of accuracy. Advisors/Committee Members: Groth, Clinton P.T., Aerospace Science and Engineering.

Subjects/Keywords: Aerospace; Combustion; Computational Fluid Dynamics; High-Order Methods; Numerical Methods; 0538

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APA (6^th Edition):

Tobaldini Neto, L. T. (2019). High-order Finite-volume CENO Scheme for Large-Eddy Simulation of Premixed Flames. (Doctoral Dissertation). University of Toronto. Retrieved from http://hdl.handle.net/1807/97004

Chicago Manual of Style (16^th Edition):

Tobaldini Neto, Luiz Tobaldini. “High-order Finite-volume CENO Scheme for Large-Eddy Simulation of Premixed Flames.” 2019. Doctoral Dissertation, University of Toronto. Accessed March 05, 2021. http://hdl.handle.net/1807/97004.

MLA Handbook (7^th Edition):

Tobaldini Neto, Luiz Tobaldini. “High-order Finite-volume CENO Scheme for Large-Eddy Simulation of Premixed Flames.” 2019. Web. 05 Mar 2021.

Vancouver:

Tobaldini Neto LT. High-order Finite-volume CENO Scheme for Large-Eddy Simulation of Premixed Flames. [Internet] [Doctoral dissertation]. University of Toronto; 2019. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/1807/97004.

Council of Science Editors:

Tobaldini Neto LT. High-order Finite-volume CENO Scheme for Large-Eddy Simulation of Premixed Flames. [Doctoral Dissertation]. University of Toronto; 2019. Available from: http://hdl.handle.net/1807/97004

University of Illinois – Urbana-Champaign

18. Liao, Kai-Pin. Solution of strained edge flames by a boundary value method.

Degree: PhD, 0133, 2014, University of Illinois – Urbana-Champaign

URL: http://hdl.handle.net/2142/49763

► Edge flames are fundamental flame structures essential to the description of flame hole dynamics in turbulent combustion and the stabilization of lifted jet flames. In… (more)

Subjects/Keywords: Edge flame; Combustion; Numerical analysis; Boundary value method

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APA (6^th Edition):

Liao, K. (2014). Solution of strained edge flames by a boundary value method. (Doctoral Dissertation). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/49763

Chicago Manual of Style (16^th Edition):

Liao, Kai-Pin. “Solution of strained edge flames by a boundary value method.” 2014. Doctoral Dissertation, University of Illinois – Urbana-Champaign. Accessed March 05, 2021. http://hdl.handle.net/2142/49763.

MLA Handbook (7^th Edition):

Liao, Kai-Pin. “Solution of strained edge flames by a boundary value method.” 2014. Web. 05 Mar 2021.

Vancouver:

Liao K. Solution of strained edge flames by a boundary value method. [Internet] [Doctoral dissertation]. University of Illinois – Urbana-Champaign; 2014. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/2142/49763.

Council of Science Editors:

Liao K. Solution of strained edge flames by a boundary value method. [Doctoral Dissertation]. University of Illinois – Urbana-Champaign; 2014. Available from: http://hdl.handle.net/2142/49763

University of Illinois – Urbana-Champaign

19. Koundinyan, Sushil. Modeling ignition and extinction in condensed phase combustion.

Degree: PhD, Theoretical & Applied Mechans, 2016, University of Illinois – Urbana-Champaign

URL: http://hdl.handle.net/2142/95456

► The characteristics of ignition and extinction in thermites and intermetallics are a subject of interest in developing the latest generation of energetic materials. An experimental… (more)

Subjects/Keywords: Condense Phase Combustion; Reaction-Diffusion; Modeling; Numerical Analysis

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APA (6^th Edition):

Koundinyan, S. (2016). Modeling ignition and extinction in condensed phase combustion. (Doctoral Dissertation). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/95456

Chicago Manual of Style (16^th Edition):

Koundinyan, Sushil. “Modeling ignition and extinction in condensed phase combustion.” 2016. Doctoral Dissertation, University of Illinois – Urbana-Champaign. Accessed March 05, 2021. http://hdl.handle.net/2142/95456.

MLA Handbook (7^th Edition):

Koundinyan, Sushil. “Modeling ignition and extinction in condensed phase combustion.” 2016. Web. 05 Mar 2021.

Vancouver:

Koundinyan S. Modeling ignition and extinction in condensed phase combustion. [Internet] [Doctoral dissertation]. University of Illinois – Urbana-Champaign; 2016. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/2142/95456.

Council of Science Editors:

Koundinyan S. Modeling ignition and extinction in condensed phase combustion. [Doctoral Dissertation]. University of Illinois – Urbana-Champaign; 2016. Available from: http://hdl.handle.net/2142/95456

University of Melbourne

20. Haghiri, Ali. Sound generation by turbulent premixed flames.

Degree: 2017, University of Melbourne

URL: http://hdl.handle.net/11343/191771

► In addition to being a significant form of noise pollution, combustion noise plays a key role in the instability of many combustion systems. The noise… (more)

▼ In addition to being a significant form of noise pollution, combustion noise plays a key role in the instability of many combustion systems. The noise generated by turbulent premixed flames deserves special attention since they are common in contemporary, low-emission gas turbines. Hence, a detailed understanding of the mechanism of sound generation by premixed flames is needed for designing quieter and safer combustion systems. This thesis presents a study of sound generation by turbulent, premixed flames using both direct numerical simulation (DNS) and theory. DNS of two round jet methane/air flames with equivalence ratios of 0.7 and 1.0 are carried out. Single step chemistry is employed to reduce the computational cost, and care is taken to resolve both the near and far fields and to avoid noise reflections at the outflow boundaries. Several significant features of these two flames are noted. These include the monopolar nature of the sound from both flames, the stoichiometric flame being significantly louder than the lean flame, and the observed frequency of peak acoustic spectral amplitude being consistent with prior experimental studies. Further, the importance of different types of so-called ''flame annihilation'' events as monopolar acoustic sources is demonstrated. A simple model describing the contribution of annihilation events to the far-field sound is then proposed. This model considers the far-field sound generated by a turbulent premixed flame as the superposition of the sound radiated by individual, spherically symmetric annihilation events that occurred throughout the flame. The results show a significant contribution by these events to the overall produced sound. A statistical analysis of the data pertaining to annihilation events is then presented. The results show that annihilation events generally feature high negative values of curvature. A strong negative correlation between the flame displacement speed and curvature is also observed. Examining different terms of the flame displacement speed during flame annihilation reveals that the reaction term has the highest contribution among the others, followed by the curvature term and lastly the normal diffusion term. The Markstein number (Ma) is also calculated for both the entire flame and annihilation events. Smaller values of Ma are obtained for the annihilation events. Finally, a new linear model for response of turbulent premixed flames to stretch during flame annihilation is proposed.

Subjects/Keywords: aeroacoustics; turbulent premixed flames; direct numerical simulation; combustion noise

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APA (6^th Edition):

Haghiri, A. (2017). Sound generation by turbulent premixed flames. (Doctoral Dissertation). University of Melbourne. Retrieved from http://hdl.handle.net/11343/191771

Chicago Manual of Style (16^th Edition):

Haghiri, Ali. “Sound generation by turbulent premixed flames.” 2017. Doctoral Dissertation, University of Melbourne. Accessed March 05, 2021. http://hdl.handle.net/11343/191771.

MLA Handbook (7^th Edition):

Haghiri, Ali. “Sound generation by turbulent premixed flames.” 2017. Web. 05 Mar 2021.

Vancouver:

Haghiri A. Sound generation by turbulent premixed flames. [Internet] [Doctoral dissertation]. University of Melbourne; 2017. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/11343/191771.

Council of Science Editors:

Haghiri A. Sound generation by turbulent premixed flames. [Doctoral Dissertation]. University of Melbourne; 2017. Available from: http://hdl.handle.net/11343/191771

University of Texas – Austin

21. Singh, Ravi Ishwar. Direct numerical simulation and reaction path analysis of titania formation in flame synthesis.

Degree: MSin Engineering, Mechanical Engineering, 2012, University of Texas – Austin

URL: http://hdl.handle.net/2152/23016

► Flame-based synthesis is an attractive industrial process for the large scale generation of nanoparticles. In this aerosol process, a gasifi ed precursor is injected into… (more)

▼ Flame-based synthesis is an attractive industrial process for the large scale generation of nanoparticles. In this aerosol process, a gasifi ed precursor is injected into a high-temperature turbulent flame, where oxidation followed by particle nucleation and other solid phase dynamics create nanoparticles. Precursor oxidation, which ultimately leads to nucleation, is strongly influenced by the turbulent flame dynamics. Here, direct numerical simulation (DNS) of a canonical homogeneous flow is used to understand the interaction between a methane/air flame and titanium tetrachloride oxidation to titania. Detailed chemical kinetics is used to describe the combustion and precursor oxidation processes. Results show that the initial precursor decomposition is heavily influenced by the gas phase temperature field. However, temperature insensitivity of subsequent reactions in the precursor oxidation pathway slow down conversion to the titania. Consequently, titania formation occurs at much longer time scales compared to that of hydrocarbon oxidation. Further, only a fraction of the precursor is converted to titania, and a signi cant amount of partially-oxidized precursor species are formed. Introducing the precursor in the oxidizer stream as opposed to the fuel stream has only a minimal impact on the oxidation dynamics. In order to understand modeling issues, the DNS results are compared with the laminar flamelet model. It is shown that the flamelet assumption qualitatively reproduces the oxidation structure. Further, reduced oxygen concentration in the near-flame location critically a ffects titania formation. The DNS results also show that titania forms on the lean and rich sides of the flame. A reaction path analysis (RPA) is conducted. The results illustrate the di ffering reaction pathways of the detailed chemical mechanism depending on the composition of the mixture. The RPA results corroborate with the DNS results that titania formation is maximized at two mixture fraction values, one on the lean side of the flame, and one on the rich side. Advisors/Committee Members: Ezekoye, Ofodike A. (advisor), Raman, Venkat (advisor).

Subjects/Keywords: Direct numerical simulation (DNS); Combustion; Turbulence; Titania; Nanoparticles; Detailed chemical kinetics

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APA (6^th Edition):

Singh, R. I. (2012). Direct numerical simulation and reaction path analysis of titania formation in flame synthesis. (Masters Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/23016

Chicago Manual of Style (16^th Edition):

Singh, Ravi Ishwar. “Direct numerical simulation and reaction path analysis of titania formation in flame synthesis.” 2012. Masters Thesis, University of Texas – Austin. Accessed March 05, 2021. http://hdl.handle.net/2152/23016.

MLA Handbook (7^th Edition):

Singh, Ravi Ishwar. “Direct numerical simulation and reaction path analysis of titania formation in flame synthesis.” 2012. Web. 05 Mar 2021.

Vancouver:

Singh RI. Direct numerical simulation and reaction path analysis of titania formation in flame synthesis. [Internet] [Masters thesis]. University of Texas – Austin; 2012. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/2152/23016.

Council of Science Editors:

Singh RI. Direct numerical simulation and reaction path analysis of titania formation in flame synthesis. [Masters Thesis]. University of Texas – Austin; 2012. Available from: http://hdl.handle.net/2152/23016

King Abdullah University of Science and Technology

22. Luca, Stefano. Premixed and Partial Premixed Turbulent Flames at High Reynolds Number.

Degree: Physical Science and Engineering (PSE) Division, 2018, King Abdullah University of Science and Technology

URL: http://hdl.handle.net/10754/628054

► Methane/air premixed and partially premixed turbulent flames at high Reynolds number are characterized using Direct Numerical Simulations (DNS) with detailed chemistry in a spatially evolving… (more)

▼ Methane/air premixed and partially premixed turbulent flames at high Reynolds number are characterized using Direct Numerical Simulations (DNS) with detailed chemistry in a spatially evolving slot Bunsen configuration. Two sets of simulations are performed. A first set of simulations with fully premixed inlet conditions is considered in order to assess the effect of turbulence on the flame. Four simulations are performed at increasing Reynolds number and up to 22400, defined based on the bulk velocity, slot width, and the reactants' properties, and 22 billion grid points, making it one of the largest simulations in turbulent combustion. The simulations feature finite rate chemistry with a 16 species mechanism. To perform these simulations, few preliminary steps were required: (i) two skeletal mechanisms were developed reducing GRI-3.0; (ii) a convergence study is performed to select the proper spatial and temporal discretization and (iii) simulations of fully developed turbulent channel flows are preformed to generate the inlet conditions of the jet. The study covers different aspects of flame-turbulence interaction. It is found that the thickness of the reaction zone is similar to that of a laminar flame, while the preheat zone has a lower mean temperature gradient, indicating flame thickening. The characteristic length scales of turbulence are investigated and the effect of the Reynolds number on these quantities is assessed. The tangential rate of strain is responsible for the production of flame surface in the mean and surface destruction is due to the curvature term. A second set of simulations with inhomogeneous inlet conditions is performed to study how partial premixing and turbulence interact with the flame and with each other. The jet Reynolds number is 5600, and a 33 species mechanism is used. The effect of the inlet fluctuations is reflected on heat release rate fluctuations, however the conditional mean is not affected. The flames show thickening of the preheat zone, and for the lowest level of mixing a slight thickening of the reaction zone is observed. The effect of partially mixed mixture on the NOx formation is analyzed and no major impact was found. Advisors/Committee Members: Bisetti, Fabrizio (advisor), Knio, Omar (committee member), Hawkes, Evatt (committee member), Roberts, William L. (committee member).

Subjects/Keywords: turbulent combustion; direct numerical simulations; premixed flames; partially premixed flames

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APA (6^th Edition):

Luca, S. (2018). Premixed and Partial Premixed Turbulent Flames at High Reynolds Number. (Thesis). King Abdullah University of Science and Technology. Retrieved from http://hdl.handle.net/10754/628054

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):

Luca, Stefano. “Premixed and Partial Premixed Turbulent Flames at High Reynolds Number.” 2018. Thesis, King Abdullah University of Science and Technology. Accessed March 05, 2021. http://hdl.handle.net/10754/628054.

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

MLA Handbook (7^th Edition):

Luca, Stefano. “Premixed and Partial Premixed Turbulent Flames at High Reynolds Number.” 2018. Web. 05 Mar 2021.

Vancouver:

Luca S. Premixed and Partial Premixed Turbulent Flames at High Reynolds Number. [Internet] [Thesis]. King Abdullah University of Science and Technology; 2018. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/10754/628054.

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

Council of Science Editors:

Luca S. Premixed and Partial Premixed Turbulent Flames at High Reynolds Number. [Thesis]. King Abdullah University of Science and Technology; 2018. Available from: http://hdl.handle.net/10754/628054

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

23. Caudal, Jean. Simulation numérique du reformage autothermique du méthane : Numerical simulation of methane autothermal reforming.

Degree: Docteur es, Energétique, 2013, Châtenay-Malabry, Ecole centrale de Paris

URL: http://www.theses.fr/2013ECAP0020

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Le syngas est un mélange gazeux de CO et H2 qui constitue un intermédiaire important dans l’industrie pétrochimique. Plusieurs approches sont utilisées pour le produire.… (more)

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Le syngas est un mélange gazeux de CO et H2 qui constitue un intermédiaire important dans l’industrie pétrochimique. Plusieurs approches sont utilisées pour le produire. L’oxydation partielle non catalytique (POX) et le reformage à la vapeur (SMR) en font partie. Le reformage auto thermique du méthane (ATR) combine quant à lui ces deux procédés au sein d’un même réacteur. L’amélioration du rendement global du procédé ATR requiert une meilleure caractérisation du comportement des gaz au sein de la chambre. La simulation numérique apparaît comme un outil efficace pour y parvenir. Pour réduire le coût CPU, c'est généralement l'approche RANS (Reynolds Average Numerical Simulation) qui est privilégiée pour la simulation complète de la chambre. Cette approche repose sur l'utilisation de modèles, parmi lesquels le modèle de combustion turbulente, qui a pour objectif de représenter les interactions entre la turbulence et la réaction chimique au sein du mélange. Plusieurs stratégies ont été proposées pour le calculer, qui bénéficient globalement d'une large expérience pour les systèmes classiques mettant en jeu la combustion. Cependant, les flammes observées dans les réacteurs ATR présentent des propriétés assez différentes de ces configurations classiques. La validité des modèles de combustion turbulente classiques doit donc y être vérifiée. L'objectif de cette thèse est de répondre à ce besoin, en testant la validité de différents modèles de combustion turbulente. La première partie du travail a consisté à analyser les propriétés des flammes CH4/O2 enrichies en vapeur d'eau à haute pression, et a notamment permis le développement d’une méthode d’évaluation des temps caractéristiques d’un système chimique. Dans un deuxième temps, une expérience numérique à l’aide d’un code DNS a été réalisée, afin de servir de référence pour tester a priori sur des configurations ATR plusieurs modèles RANS de combustion turbulente couramment utilisés dans le milieu industriel.

Syngas is a gaseous mixture mainly composed of CO and H2, which constitutes a major feedstock in petrochemical industry. Several industrial approaches are commonly used to produce it. Non catalytic Partial Oxidation (POX) and Steam Methane Reforming (SMR) are two of them. Autothermal Reforming (ATR) is a third process that combines both POX and SMR in the same reactor. A better knowledge of the reactive flow properties inside the chamber is required in order to improve the ATR process efficiency. Numerical simulation appears as an efficient tool to reach this goal. Because of the high CPU cost required for these simulations, RANS (Reynolds Average Numerical Simulation) formulation is usually preferred for the simulation of the whole chamber. This approach relies on the use of models, like the turbulent combustion model that aims at describing the interactions between turbulence and chemical reactions. Several approaches have been proposed to compute it, which benefit from a relatively wide experience for the simulation of classical combustion systems. However, ATR…

Advisors/Committee Members: Gicquel, Olivier (thesis director).

Subjects/Keywords: Reformage autothermique du méthane; Simulation numérique directe; Modèle de combustion turbulente; Methane autothermal reforming; Direct numerical simulation; Turbulent combustion model

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APA (6^th Edition):

Caudal, J. (2013). Simulation numérique du reformage autothermique du méthane : Numerical simulation of methane autothermal reforming. (Doctoral Dissertation). Châtenay-Malabry, Ecole centrale de Paris. Retrieved from http://www.theses.fr/2013ECAP0020

Chicago Manual of Style (16^th Edition):

Caudal, Jean. “Simulation numérique du reformage autothermique du méthane : Numerical simulation of methane autothermal reforming.” 2013. Doctoral Dissertation, Châtenay-Malabry, Ecole centrale de Paris. Accessed March 05, 2021. http://www.theses.fr/2013ECAP0020.

MLA Handbook (7^th Edition):

Caudal, Jean. “Simulation numérique du reformage autothermique du méthane : Numerical simulation of methane autothermal reforming.” 2013. Web. 05 Mar 2021.

Vancouver:

Caudal J. Simulation numérique du reformage autothermique du méthane : Numerical simulation of methane autothermal reforming. [Internet] [Doctoral dissertation]. Châtenay-Malabry, Ecole centrale de Paris; 2013. [cited 2021 Mar 05]. Available from: http://www.theses.fr/2013ECAP0020.

Council of Science Editors:

Caudal J. Simulation numérique du reformage autothermique du méthane : Numerical simulation of methane autothermal reforming. [Doctoral Dissertation]. Châtenay-Malabry, Ecole centrale de Paris; 2013. Available from: http://www.theses.fr/2013ECAP0020

24. Hervo, Loïc. Simulation numérique de l’écoulement d’un mélange air et phase dispersée pour l’allumage d’une chambre de combustion aéronautique via un formalisme Euler Lagrange : Numerical simulation of an air flow with a dispersed phase for the ignition of an aeronautical combustion chamber with an Euler Lagrange method.

Degree: Docteur es, Energétique et transferts, 2017, Toulouse, ISAE

URL: http://www.theses.fr/2017ESAE0043

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L'objectif de cette thèse est de contribuer au développement et à la validation d'outils numériques permettant la Simulation aux Grandes Echelles (SGE) de l'allumage d'un… (more)

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L'objectif de cette thèse est de contribuer au développement et à la validation d'outils numériques permettant la Simulation aux Grandes Echelles (SGE) de l'allumage d'un écoulement turbulent diphasique dans une chambre de combustion. Pour ce faire, une méthode de dépôt d'énergie modélisant l'apport d'énergie lié au claquage de la bougie d'allumage a été implémentée dans la chaîne de calcul CEDRE. Cette méthode a été validée sur une simulation de l'allumage d'un écoulement laminaire purement gazeux d'air et de propane. Une SGE de l'écoulement d'air du MERCATO a été effectué à l'aide du solveur Navier-Stokes CHARME de CEDRE. Cette simulation reproduit fidèlement l'écoulement turbulent non-réactif dans la chambre de combustion. Une méthode d'injection simplifiée FIMUR a été ajoutée au solveur lagrangien SPARTE de CEDRE. Dans cette méthode, des gouttes sont injectées directement au nez de l'injecteur avec une distribution de vitesse et de taille imposée. Une SGE de l'écoulement turbulent diphasique dispersé non-réactif dans la chambre MERCATO a ensuite été réalisée avec cette méthode. La comparaison des champs particulaires moyens de vitesse et de taille obtenus par simulation numérique avec les données expérimentales est satisfaisante. Enfin, des SGE de l'allumage de la chambre MERCATO ont été effectuées à partir du champ diphasique non-réactif simulé et de la méthode de dépôt d'énergie développée. Selon l'instant du dépôt d'énergie, les simulations conduisent à des allumages réussis ou ratés. La propagation de la flamme dans la chambre pour un allumage réussi a fait l'objet d'une analyse détaillée pour tenter de déterminer les principaux facteurs l'influençant.

The goal of this thesis is to contribute to the development and validation of numerical tools for the Large Eddy Simulation (LES) of the ignition of a turbulent multiphase flow in a combustion chamber. An energy deposition method that models the energy supplied by the spark plug to the flow was implemented in the CEDRE code. This method was validated on a simulation of the ignition of a purely gaseous laminar propane-air flow. Then, a LES of the non-reacting gas flow in the monosector combustor MERCATO was performed with the Navier-Stokes solver CHARME of the CEDRE code. The comparison between simulations and experiments demonstrates that the main flow field features are well reproduced. In order to simulate the non-reacting dispersed two-phase flow of the same configuration, a simplified injection method called FIMUR was implemented in the Lagrangian solver SPARTE of the CEDRE code. In this method, droplets are injected directly at the tip of the injector with velocities deduced from experimental correlations while the size distribution is directly obtained from experimental data. The comparison of the mean droplet velocity and diameter fields in the vicinity of the injector between simulations and experiments appears satisfactory. Finally, LES's of the ignition of the MERCATO were performed using the non-reacting two-phase flow simulations and the…

Advisors/Committee Members: Cuenot, Bénédicte (thesis director), Senoner, Jean-Mathieu (thesis director).

Subjects/Keywords: Simulation numérique; Écoulement diphasique; Combustion; Allumage; Spray; Euler-Lagrange; Numerical simulation; Multiphase flow; Combustion; Ignition; Spray; Euler-Lagrange; 532

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

APA (6^th Edition):

Hervo, L. (2017). Simulation numérique de l’écoulement d’un mélange air et phase dispersée pour l’allumage d’une chambre de combustion aéronautique via un formalisme Euler Lagrange : Numerical simulation of an air flow with a dispersed phase for the ignition of an aeronautical combustion chamber with an Euler Lagrange method. (Doctoral Dissertation). Toulouse, ISAE. Retrieved from http://www.theses.fr/2017ESAE0043

Chicago Manual of Style (16^th Edition):

Hervo, Loïc. “Simulation numérique de l’écoulement d’un mélange air et phase dispersée pour l’allumage d’une chambre de combustion aéronautique via un formalisme Euler Lagrange : Numerical simulation of an air flow with a dispersed phase for the ignition of an aeronautical combustion chamber with an Euler Lagrange method.” 2017. Doctoral Dissertation, Toulouse, ISAE. Accessed March 05, 2021. http://www.theses.fr/2017ESAE0043.

MLA Handbook (7^th Edition):

Hervo, Loïc. “Simulation numérique de l’écoulement d’un mélange air et phase dispersée pour l’allumage d’une chambre de combustion aéronautique via un formalisme Euler Lagrange : Numerical simulation of an air flow with a dispersed phase for the ignition of an aeronautical combustion chamber with an Euler Lagrange method.” 2017. Web. 05 Mar 2021.

Vancouver:

Hervo L. Simulation numérique de l’écoulement d’un mélange air et phase dispersée pour l’allumage d’une chambre de combustion aéronautique via un formalisme Euler Lagrange : Numerical simulation of an air flow with a dispersed phase for the ignition of an aeronautical combustion chamber with an Euler Lagrange method. [Internet] [Doctoral dissertation]. Toulouse, ISAE; 2017. [cited 2021 Mar 05]. Available from: http://www.theses.fr/2017ESAE0043.

Council of Science Editors:

Hervo L. Simulation numérique de l’écoulement d’un mélange air et phase dispersée pour l’allumage d’une chambre de combustion aéronautique via un formalisme Euler Lagrange : Numerical simulation of an air flow with a dispersed phase for the ignition of an aeronautical combustion chamber with an Euler Lagrange method. [Doctoral Dissertation]. Toulouse, ISAE; 2017. Available from: http://www.theses.fr/2017ESAE0043

INP Toulouse

25. Collado Morata, Elena. Impact of the unsteady aerothermal environment on the turbine blades temperature : Analyse de l'impact de l'environnement aérothermique instationnaire sur la température des pales de turbine HP.

Degree: Docteur es, Energétique et Transferts, 2012, INP Toulouse

URL: http://www.theses.fr/2012INPT0094

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Ce travail de thèse, menée dans le cadre d'une convention CIFRE entre TURBOMECA et le CERFACS, s'inscrit dans un contexte d'amélioration des performances des turbines… (more)

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Ce travail de thèse, menée dans le cadre d'une convention CIFRE entre TURBOMECA et le CERFACS, s'inscrit dans un contexte d'amélioration des performances des turbines de type axial équipant les turboréacteurs d'hélicoptère. L'une des principales difficultés rencontrée dans cette démarche concerne la maîtrise de la température que voient les pales de ce composant, notamment la roue haute pression. Les travaux de cette thèse s'articulent autour de deux axes principaux: - Le premier traite l'analyse de la Simulations aux Grandes Echelles (SGE) autour de pales. Une approche numérique SGE sur des maillages non-structurés est comparée aux résultats Reynolds Averaged Navier-Stokes (RANS) sur des maillages structurés, usuels dans ce type de configuration, ainsi qu'à une approche SGE sur maillages structurés. La SGE sur maillage non-structuré démontre sa capacité à prendre en compte les phénomènes qui ont un impact sur les flux de chaleur pariétaux. - Le second axe de recherche a pour objectif de développer un outil numérique de couplage pour assurer le transfert d'information entre un code SGE réactif sur maillage non-structuré, employé dans les chambres de combustion, et un code non-réactif en RANS, utilisé par les industriels pour modéliser l'étage turbine. Cet outil a été validé sur plusieurs cas tests qui montrent le potentiel de cette méthodologie pour le couplage multi-composant.

This PhD dissertation, conducted as part of a CIFRE research project between TURBOMECA and CERFACS, deals with improving performance of axial turbines from helicopter engines. One of the main difficulties with such an objective is the control of the temperature prediction around the blades, especially the temperature of the high pressure rotor. The work of this thesis focusses on two axes: - First concerns the analysis of Large Eddy Simulation (LES) predictions around blades: a numerical LES approach on unstructured meshes is compared to Reynolds Averaged Navier-Stokes (RANS) results on structured meshes as well as to LES on structured meshes. LES on unstructured meshes demonstrates its capacity of taking into account the phenomena which have an impact on wall heat flux around blades. - The second axis deals with the development of a numerical tool for coupling and transferring information between a reactive LES code, used in combustion chambers, and a non-reactive RANS solver, employed by industrial actors for modeling the turbine stage. This tool is validated on a number of test cases which show the potential of this methodology for multi-component predictions.

Advisors/Committee Members: Gicquel, Laurent (thesis director), Gourdain, Nicolas (thesis director).

Subjects/Keywords: Interaction chambre de combustion-turbine; Transfert de chaleur; Simulation numérique; Couplage; Combustion chamber-turbine interaction; Heat transfer; Numerical simulation; Coupling

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

APA (6^th Edition):

Collado Morata, E. (2012). Impact of the unsteady aerothermal environment on the turbine blades temperature : Analyse de l'impact de l'environnement aérothermique instationnaire sur la température des pales de turbine HP. (Doctoral Dissertation). INP Toulouse. Retrieved from http://www.theses.fr/2012INPT0094

Chicago Manual of Style (16^th Edition):

Collado Morata, Elena. “Impact of the unsteady aerothermal environment on the turbine blades temperature : Analyse de l'impact de l'environnement aérothermique instationnaire sur la température des pales de turbine HP.” 2012. Doctoral Dissertation, INP Toulouse. Accessed March 05, 2021. http://www.theses.fr/2012INPT0094.

MLA Handbook (7^th Edition):

Collado Morata, Elena. “Impact of the unsteady aerothermal environment on the turbine blades temperature : Analyse de l'impact de l'environnement aérothermique instationnaire sur la température des pales de turbine HP.” 2012. Web. 05 Mar 2021.

Vancouver:

Collado Morata E. Impact of the unsteady aerothermal environment on the turbine blades temperature : Analyse de l'impact de l'environnement aérothermique instationnaire sur la température des pales de turbine HP. [Internet] [Doctoral dissertation]. INP Toulouse; 2012. [cited 2021 Mar 05]. Available from: http://www.theses.fr/2012INPT0094.

Council of Science Editors:

Collado Morata E. Impact of the unsteady aerothermal environment on the turbine blades temperature : Analyse de l'impact de l'environnement aérothermique instationnaire sur la température des pales de turbine HP. [Doctoral Dissertation]. INP Toulouse; 2012. Available from: http://www.theses.fr/2012INPT0094

26. Lim, Kian Min. DNS of inhomogeneous reactants premixed combustion.

Degree: PhD, 2015, University of Cambridge

URL: https://doi.org/10.17863/CAM.14088 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.646274

► The search for clean and efficient combustors is motivated by the increasingly stringent emissions regulations. New gas turbine engines are designed to operate under lean… (more)

▼ The search for clean and efficient combustors is motivated by the increasingly stringent emissions regulations. New gas turbine engines are designed to operate under lean conditions with inhomogeneous reactants to ensure cleanliness and stability of the combustion. This ushers in a new mode of combustion, called the inhomogeneous reactants premixed combustion. The present study investigates the effects of inhomogeneous reactants on premixed combustion, specifically on the interactions of an initially planar flame with field of inhomogeneous reactants. Unsteady and unstrained laminar methane-air flames are studied in one- and two-dimensional simulations to investigate the effects of normally and tangentially (to the flame surface) stratified reactants. A three-dimensional DNS of turbulent inhomogeneous reactants premixed combustion is performed to extend the investigation into turbulent flames. The methaneair combustion is represented by a complex chemical reaction mechanism with 18 species and 68 steps. The flame surface density (FSD) and displacement speed S_d have been used as the framework to analyse the inhomogeneous reactants premixed flame. The flames are characterised by an isosurface of reaction progress variable. The unsteady flames are compared to the steady laminar unstrained reference case. An equivalence ratio dip is observed in all simulations and it can serve as a marker for the premixed flame. The dip is attributed to the preferential diffusion of carbon- and hydrogen- containing species. Hysteresis of S_d is observed in the unsteady and unstrained laminar flames that propagate into normally stratified reactants. Stoichiometric flames propagating into lean mixture have a larger S_d than lean flames propagating into stoichiometric mixtures. The cross-dissipation term contribution to S_d is small (~~10%) but its contribution to the hysteresis of S_d is not (~~50%). Differential propagation of the flame surface is observed in the laminar flame that propagates into tangentially stratified reactants. Stretch on the flame surface is induced by the differential propagation, which in turn increases the flame surface area.

Subjects/Keywords: 621.43; Inhomogeneous reactants premixed combustion; Premixed combustion; Direct numerical simulation (DNS); Progress variable; Flame surface density (FSD); Displacement speed

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

APA (6^th Edition):

Lim, K. M. (2015). DNS of inhomogeneous reactants premixed combustion. (Doctoral Dissertation). University of Cambridge. Retrieved from https://doi.org/10.17863/CAM.14088 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.646274

Chicago Manual of Style (16^th Edition):

Lim, Kian Min. “DNS of inhomogeneous reactants premixed combustion.” 2015. Doctoral Dissertation, University of Cambridge. Accessed March 05, 2021. https://doi.org/10.17863/CAM.14088 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.646274.

MLA Handbook (7^th Edition):

Lim, Kian Min. “DNS of inhomogeneous reactants premixed combustion.” 2015. Web. 05 Mar 2021.

Vancouver:

Lim KM. DNS of inhomogeneous reactants premixed combustion. [Internet] [Doctoral dissertation]. University of Cambridge; 2015. [cited 2021 Mar 05]. Available from: https://doi.org/10.17863/CAM.14088 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.646274.

Council of Science Editors:

Lim KM. DNS of inhomogeneous reactants premixed combustion. [Doctoral Dissertation]. University of Cambridge; 2015. Available from: https://doi.org/10.17863/CAM.14088 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.646274

University of Cambridge

27. Lim, Kian Min. DNS of inhomogeneous reactants premixed combustion.

Degree: PhD, 2015, University of Cambridge

URL: https://www.repository.cam.ac.uk/handle/1810/247342https://www.repository.cam.ac.uk/bitstream/1810/247342/2/license.txt ; https://www.repository.cam.ac.uk/bitstream/1810/247342/3/Kian%20Min%20Lim%20Thesis.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/247342/5/Kian%20Min%20Lim%20Thesis%20Abstract.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/247342/6/Kian%20Min%20Lim%20Thesis%20Abstract.pdf.jpg ; https://www.repository.cam.ac.uk/bitstream/1810/247342/7/Kian%20Min%20Lim%20Thesis.pdf.jpg

► The search for clean and efficient combustors is motivated by the increasingly stringent emissions regulations. New gas turbine engines are designed to operate under lean… (more)

▼ The search for clean and efficient combustors is motivated by the increasingly stringent emissions regulations. New gas turbine engines are designed to operate under lean conditions with inhomogeneous reactants to ensure cleanliness and stability of the combustion. This ushers in a new mode of combustion, called the inhomogeneous reactants premixed combustion. The present study investigates the effects of inhomogeneous reactants on premixed combustion, specifically on the interactions of an initially planar flame with field of inhomogeneous reactants. Unsteady and unstrained laminar methane-air flames are studied in one- and two-dimensional simulations to investigate the effects of normally and tangentially (to the flame surface) stratified reactants. A three-dimensional DNS of turbulent inhomogeneous reactants premixed combustion is performed to extend the investigation into turbulent flames. The methaneair combustion is represented by a complex chemical reaction mechanism with 18 species and 68 steps. The flame surface density (FSD) and displacement speed S_d have been used as the framework to analyse the inhomogeneous reactants premixed flame. The flames are characterised by an isosurface of reaction progress variable. The unsteady flames are compared to the steady laminar unstrained reference case. An equivalence ratio dip is observed in all simulations and it can serve as a marker for the premixed flame. The dip is attributed to the preferential diffusion of carbon- and hydrogen- containing species. Hysteresis of S_d is observed in the unsteady and unstrained laminar flames that propagate into normally stratified reactants. Stoichiometric flames propagating into lean mixture have a larger S_d than lean flames propagating into stoichiometric mixtures. The cross-dissipation term contribution to S_d is small (~~10%) but its contribution to the hysteresis of S_d is not (~~50%). Differential propagation of the flame surface is observed in the laminar flame that propagates into tangentially stratified reactants. Stretch on the flame surface is induced by the differential propagation, which in turn increases the flame surface area.

Subjects/Keywords: Inhomogeneous reactants premixed combustion; Premixed combustion; Direct numerical simulation (DNS); Progress variable; Flame surface density (FSD); Displacement speed

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

APA (6^th Edition):

Lim, K. M. (2015). DNS of inhomogeneous reactants premixed combustion. (Doctoral Dissertation). University of Cambridge. Retrieved from https://www.repository.cam.ac.uk/handle/1810/247342https://www.repository.cam.ac.uk/bitstream/1810/247342/2/license.txt ; https://www.repository.cam.ac.uk/bitstream/1810/247342/3/Kian%20Min%20Lim%20Thesis.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/247342/5/Kian%20Min%20Lim%20Thesis%20Abstract.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/247342/6/Kian%20Min%20Lim%20Thesis%20Abstract.pdf.jpg ; https://www.repository.cam.ac.uk/bitstream/1810/247342/7/Kian%20Min%20Lim%20Thesis.pdf.jpg

Chicago Manual of Style (16^th Edition):

Lim, Kian Min. “DNS of inhomogeneous reactants premixed combustion.” 2015. Doctoral Dissertation, University of Cambridge. Accessed March 05, 2021. https://www.repository.cam.ac.uk/handle/1810/247342https://www.repository.cam.ac.uk/bitstream/1810/247342/2/license.txt ; https://www.repository.cam.ac.uk/bitstream/1810/247342/3/Kian%20Min%20Lim%20Thesis.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/247342/5/Kian%20Min%20Lim%20Thesis%20Abstract.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/247342/6/Kian%20Min%20Lim%20Thesis%20Abstract.pdf.jpg ; https://www.repository.cam.ac.uk/bitstream/1810/247342/7/Kian%20Min%20Lim%20Thesis.pdf.jpg.

MLA Handbook (7^th Edition):

Lim, Kian Min. “DNS of inhomogeneous reactants premixed combustion.” 2015. Web. 05 Mar 2021.

Vancouver:

Lim KM. DNS of inhomogeneous reactants premixed combustion. [Internet] [Doctoral dissertation]. University of Cambridge; 2015. [cited 2021 Mar 05]. Available from: https://www.repository.cam.ac.uk/handle/1810/247342https://www.repository.cam.ac.uk/bitstream/1810/247342/2/license.txt ; https://www.repository.cam.ac.uk/bitstream/1810/247342/3/Kian%20Min%20Lim%20Thesis.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/247342/5/Kian%20Min%20Lim%20Thesis%20Abstract.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/247342/6/Kian%20Min%20Lim%20Thesis%20Abstract.pdf.jpg ; https://www.repository.cam.ac.uk/bitstream/1810/247342/7/Kian%20Min%20Lim%20Thesis.pdf.jpg.

Council of Science Editors:

Lim KM. DNS of inhomogeneous reactants premixed combustion. [Doctoral Dissertation]. University of Cambridge; 2015. Available from: https://www.repository.cam.ac.uk/handle/1810/247342https://www.repository.cam.ac.uk/bitstream/1810/247342/2/license.txt ; https://www.repository.cam.ac.uk/bitstream/1810/247342/3/Kian%20Min%20Lim%20Thesis.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/247342/5/Kian%20Min%20Lim%20Thesis%20Abstract.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/247342/6/Kian%20Min%20Lim%20Thesis%20Abstract.pdf.jpg ; https://www.repository.cam.ac.uk/bitstream/1810/247342/7/Kian%20Min%20Lim%20Thesis.pdf.jpg

28. Pelletier, Milan. Diffuse interface models and adapted numerical schemes for the simulation of subcritical to supercritical flows : Étude des modèles d’interface diffuse et des schémas numériques adaptés pour la simulation d’écoulements sous-critiques à supercritiques.

Degree: Docteur es, Énergétique, 2019, Université Paris-Saclay (ComUE)

URL: http://www.theses.fr/2019SACLC059

►

Au cours de l’utilisation de certains systèmes propulsifs, tels que les moteurs fusées cryotechniques ou les moteurs Diesel, le point de fonctionnement peut varier sur… (more)

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Au cours de l’utilisation de certains systèmes propulsifs, tels que les moteurs fusées cryotechniques ou les moteurs Diesel, le point de fonctionnement peut varier sur une large plage de pressions. Ces variations de pression peuvent conduire à un changement de régime thermodynamique si la pression critique du fluide est franchie, l’injection initialement diphasique devenant alors transcritique. Ce changement modifie la topologie de l’écoulement, ainsi que la dynamique du mélange, ce qui impacte le comportement de la flamme. L’objectif de cette thèse est de développer une méthodologie originale capable de traiter au sein du même solveur des écoulements sous-critiques ainsi que supercritiques. Pour cela, une extension du solveur AVBP-RG aux écoulements diphasiques sous-critiques est proposée, basée sur des modèles d’interface diffuse. Les développements nécessaires à l’intégration de ces modèles dans le cadre du solveur aux éléments finis sont effectués. Des simulations numériques multidimensionnelles sont ensuite proposées de manière à confronter le modèle à des données exprérimentales, vis-à-vis desquelles un bon accord est observé. Cesrésultats offrent des perspectives encourageantes vers de futures améliorations du modèle et des applications à des configurations industrielles complexes.

In various industrial combustion devices, such as liquid rocket engines at ignition or Diesel engines during the compression stage, the operating point varies over a wide range of pressures. These pressure variations can lead to a change of thermodynamic regime when the critical pressure is exceeded, switching from two-phase injection to transcritical injection. This change modifies the topology of the flow and the mixing, thereby impacting the flame dynamics. The objective of the present Ph.D thesis is to develop an original methodology able to address both subcritical and supercritical flows within the same solver. To achieve this, an extension of the real gas solver AVBP-RG to subcritical two-phase flows is provided, based on diffuse interface models. The required developments for the integration of such models into the finite-element framework of the solver are provided. Multidimensional numerical simulations are led in order to confront the model with experimental data, with which good agreement is observed. These results offer encouraging perspectives regarding further enhancements of the model and applications to complex industrial cases.

Advisors/Committee Members: Ducruix, Sébastien (thesis director).

Subjects/Keywords: Écoulements diphasiques; É́coulements supercritiques; Thermodynamique gaz réel; Méthodes numériques; Combustion; Two-Phase flows; Supercritical flows; Real gas thermodynamics; Numerical methods; Combustion

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

APA (6^th Edition):

Pelletier, M. (2019). Diffuse interface models and adapted numerical schemes for the simulation of subcritical to supercritical flows : Étude des modèles d’interface diffuse et des schémas numériques adaptés pour la simulation d’écoulements sous-critiques à supercritiques. (Doctoral Dissertation). Université Paris-Saclay (ComUE). Retrieved from http://www.theses.fr/2019SACLC059

Chicago Manual of Style (16^th Edition):

Pelletier, Milan. “Diffuse interface models and adapted numerical schemes for the simulation of subcritical to supercritical flows : Étude des modèles d’interface diffuse et des schémas numériques adaptés pour la simulation d’écoulements sous-critiques à supercritiques.” 2019. Doctoral Dissertation, Université Paris-Saclay (ComUE). Accessed March 05, 2021. http://www.theses.fr/2019SACLC059.

MLA Handbook (7^th Edition):

Pelletier, Milan. “Diffuse interface models and adapted numerical schemes for the simulation of subcritical to supercritical flows : Étude des modèles d’interface diffuse et des schémas numériques adaptés pour la simulation d’écoulements sous-critiques à supercritiques.” 2019. Web. 05 Mar 2021.

Vancouver:

Pelletier M. Diffuse interface models and adapted numerical schemes for the simulation of subcritical to supercritical flows : Étude des modèles d’interface diffuse et des schémas numériques adaptés pour la simulation d’écoulements sous-critiques à supercritiques. [Internet] [Doctoral dissertation]. Université Paris-Saclay (ComUE); 2019. [cited 2021 Mar 05]. Available from: http://www.theses.fr/2019SACLC059.

Council of Science Editors:

Pelletier M. Diffuse interface models and adapted numerical schemes for the simulation of subcritical to supercritical flows : Étude des modèles d’interface diffuse et des schémas numériques adaptés pour la simulation d’écoulements sous-critiques à supercritiques. [Doctoral Dissertation]. Université Paris-Saclay (ComUE); 2019. Available from: http://www.theses.fr/2019SACLC059

Princeton University

29. Novoselov, Alex Gregory. Manifold-Based Modeling of Turbulent Reacting Flows: Cool Flames and Multi-Modal Combustion .

Degree: PhD, 2020, Princeton University

URL: http://arks.princeton.edu/ark:/88435/dsp01qb98mj40s

► Simulation tools are becoming progressively more important in industrial settings because of their ability to facilitate the design of increasingly efficient combustion systems. In particular,… (more)

▼ Simulation tools are becoming progressively more important in industrial settings because of their ability to facilitate the design of increasingly efficient combustion systems. In particular, Large Eddy Simulation (LES) stands out as both an accurate and computationally affordable method to simulate quantities of interest in turbulent reacting flows. However, it requires models for unclosed combustion terms that are simultaneously physically accurate and computationally affordable. One traditional closure approach is that of a manifold-based model that restricts the thermochemical state to some lower-dimensional manifold based on physical assumptions. Because of the low dimensionality of the manifold space, such models are very computationally efficient. However, their generality suffers due to restrictive physical assumptions about the flame's structure. This dissertation seeks to generalize manifold-based turbulent combustion models. First, the capability of traditional manifold-based models in describing turbulent cool flames is explored. A combined experimental and computational study of a turbulent nonpremixed jet cool flame lays the foundation for the study. Experimental measurements agree well with Direct Numerical Simulation (DNS) results, which in turn agree well with solutions to nonpremixed manifold equations, indicating that nonpremixed manifold-based models can describe turbulent cool flames. Additional DNS are performed in order to study the effect of the Damkoehler number on manifold-based model validity, which suggest that multi-modal combustion is relevant at low Damkoehler numbers. The states locally identified as nonpremixed are still found to be well described by a traditional manifold-based model, but describing all states requires a more general multi-modal model. Such a multi-modal manifold-based combustion model is then developed using two-dimensional manifold equations. The need for this model is examined through multiple laminar flame configurations, and closure for the dissipation rates is achieved. A new In-Situ Adaptive Manifolds approach is developed to overcome computational tractability issues, and the model is applied to LES of a multi-modal turbulent lifted jet flame. The cost per timestep is comparable to traditional manifold-based models for a single asymptotic mode, indicating that this model generality comes at no additional computational overhead. Additionally, the model allows for simple combustion mode analysis through examination of the local dissipation rates and source terms. Advisors/Committee Members: Mueller, Michael E (advisor).

Subjects/Keywords: Cool Flames; Direct Numerical Simulation (DNS); Large Eddy Simulation (LES); Manifold-Based Modeling; Multi-Modal Combustion; Turbulent Combustion

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

APA (6^th Edition):

Novoselov, A. G. (2020). Manifold-Based Modeling of Turbulent Reacting Flows: Cool Flames and Multi-Modal Combustion . (Doctoral Dissertation). Princeton University. Retrieved from http://arks.princeton.edu/ark:/88435/dsp01qb98mj40s

Chicago Manual of Style (16^th Edition):

Novoselov, Alex Gregory. “Manifold-Based Modeling of Turbulent Reacting Flows: Cool Flames and Multi-Modal Combustion .” 2020. Doctoral Dissertation, Princeton University. Accessed March 05, 2021. http://arks.princeton.edu/ark:/88435/dsp01qb98mj40s.

MLA Handbook (7^th Edition):

Novoselov, Alex Gregory. “Manifold-Based Modeling of Turbulent Reacting Flows: Cool Flames and Multi-Modal Combustion .” 2020. Web. 05 Mar 2021.

Vancouver:

Novoselov AG. Manifold-Based Modeling of Turbulent Reacting Flows: Cool Flames and Multi-Modal Combustion . [Internet] [Doctoral dissertation]. Princeton University; 2020. [cited 2021 Mar 05]. Available from: http://arks.princeton.edu/ark:/88435/dsp01qb98mj40s.

Council of Science Editors:

Novoselov AG. Manifold-Based Modeling of Turbulent Reacting Flows: Cool Flames and Multi-Modal Combustion . [Doctoral Dissertation]. Princeton University; 2020. Available from: http://arks.princeton.edu/ark:/88435/dsp01qb98mj40s

30. Nguyen, Khac Tien. Dégradation thermique de matériaux solides poreux exposés au feu - Simulation numérique avec prise en compte des processus chimiques et mécanismes de transfert : Thermal degradation of solid porous materials exposed to fire - Numerical simulation accounting for chemical processes and tranfer mechanisms.

Degree: Docteur es, Energie, thermique, combustion, 2014, Poitiers

URL: http://www.theses.fr/2014POIT2344

►

La description de la dégradation des solides est cruciale dans la simulation numérique d'un feu, les gaz de pyrolyse constituant la source combustible amenée au… (more)

▼

La description de la dégradation des solides est cruciale dans la simulation numérique d'un feu, les gaz de pyrolyse constituant la source combustible amenée au feu. Il importe de décrire avec précision ces processus en fonction des conditions ambiantes. Toutefois, les couplages entre réactions chimiques et mécanismes de transport de masse et de chaleur modifient fortement les comportements. L'objet de ce travail est la prédiction du comportement macroscopique par simulation numérique de la décomposition thermique des matériaux solides. Les propriétés intrinsèques du matériau, parmi lesquelles un modèle chimique incluant un schéma réactionnel et les paramètres thermocinétiques associés, issus d'expérimentation à petite échelle sont considérés ainsi que les mécanismes de transport et les effets limitants qu'ils peuvent introduire. La réponse du matériau est ainsi prédite pour des configurations géométriques et des scénarios d'exposition arbitraires. L’outil spécifique développé au cours de ce doctorat est basé sur une description à l'échelle de Darcy. Il a pour objectif à terme d’être couplé à un code de simulation du feu dans son ensemble, de sorte que les conditions auxquelles chaque élément solide serait exposé seraient décrites tandis que la prédiction de l'évolution du feu dépendrait de la réponse des matériaux fournie par notre module. Un jeu d'applications est présenté pour deux types de bois ayant des schémas réactionnels différents, avec réactions séquentielles ou concurrentielles. Les configurations et scénarios examinés correspondent à des essais normalisés, sous cône calorimètre, et une comparaison entre les résultats numériques et expérimentaux est effectuée.

The description of the degradation of solids is crucial in the numerical simulation of a fire, the pyrolysis gases constituting the combustible source. It is important to describe with accuracy these processes, according to the ambient conditions. However, the couplings between chemical reactions and mechanisms of mass and heat transports strongly modify the behavior of the fire.The objective of this work is to predict the macroscopic behavior of the thermal decomposition of solid fuel by numerical simulation. The intrinsic properties of the material, among which a chemical model including a reactive scheme and the associated thermochemical parameters stemming from small-scale experiment are considered as well as the transport mechanisms and the limiting effects that they can introduce. The comportment of the material is then predicted for geometrical configurations and arbitrary scenarios of exposure. The specific tool developed during this Ph-D is based on a description on the Darcy scale. It has in the future to be coupled with a global code of simulation of the fire, so that the conditions undergone by every exposed solid element would be described whereas the prediction of the fire evolution fire would depend on the behavior of the materials supplied by the present module.A set of applications is presented for two wooden materials, featuring…

Advisors/Committee Members: Thovert, Jean-François (thesis director), Rogaume, Thomas (thesis director).

Subjects/Keywords: Pyrolyse; Combustion; Milieux poreux; Simulation numérique; Sécurité incendie; Pyrolysis; Combustion; Porous medium; Numerical simulation; Fire security; 620.1

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

APA (6^th Edition):

Nguyen, K. T. (2014). Dégradation thermique de matériaux solides poreux exposés au feu - Simulation numérique avec prise en compte des processus chimiques et mécanismes de transfert : Thermal degradation of solid porous materials exposed to fire - Numerical simulation accounting for chemical processes and tranfer mechanisms. (Doctoral Dissertation). Poitiers. Retrieved from http://www.theses.fr/2014POIT2344

Chicago Manual of Style (16^th Edition):

Nguyen, Khac Tien. “Dégradation thermique de matériaux solides poreux exposés au feu - Simulation numérique avec prise en compte des processus chimiques et mécanismes de transfert : Thermal degradation of solid porous materials exposed to fire - Numerical simulation accounting for chemical processes and tranfer mechanisms.” 2014. Doctoral Dissertation, Poitiers. Accessed March 05, 2021. http://www.theses.fr/2014POIT2344.

MLA Handbook (7^th Edition):

Nguyen, Khac Tien. “Dégradation thermique de matériaux solides poreux exposés au feu - Simulation numérique avec prise en compte des processus chimiques et mécanismes de transfert : Thermal degradation of solid porous materials exposed to fire - Numerical simulation accounting for chemical processes and tranfer mechanisms.” 2014. Web. 05 Mar 2021.

Vancouver:

Nguyen KT. Dégradation thermique de matériaux solides poreux exposés au feu - Simulation numérique avec prise en compte des processus chimiques et mécanismes de transfert : Thermal degradation of solid porous materials exposed to fire - Numerical simulation accounting for chemical processes and tranfer mechanisms. [Internet] [Doctoral dissertation]. Poitiers; 2014. [cited 2021 Mar 05]. Available from: http://www.theses.fr/2014POIT2344.

Council of Science Editors:

Nguyen KT. Dégradation thermique de matériaux solides poreux exposés au feu - Simulation numérique avec prise en compte des processus chimiques et mécanismes de transfert : Thermal degradation of solid porous materials exposed to fire - Numerical simulation accounting for chemical processes and tranfer mechanisms. [Doctoral Dissertation]. Poitiers; 2014. Available from: http://www.theses.fr/2014POIT2344

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Open Access Theses and Dissertations