Azeddine Soudani - Academia.edu (original) (raw)
Papers by Azeddine Soudani
Mathematical modelling of engineering problems, Aug 31, 2021
The first objective of this numerical research is to help understand the influence of variable de... more The first objective of this numerical research is to help understand the influence of variable density on the structure of turbulence, through the study of a wall jet, and to validate our results with those of the experimental study of A. Soudani. The source of density variation is the mixture between two different non-reactive fluids, with a fixed temperature and pressure. A mass weighted averaging for different variables is applied to the calculation, using ANSYS FLUENT 15.0 commercial software. The principal experience consists of injecting tangentially and alternatively near the wall a gas (airhelium) different from the external flow, through a slot of height 3mm between two plane walls. Such a process permits to provoke an important density difference. The study reaches the conclusion that turbulence is strong, with a slight increase of velocity near the wall and an evident diminution of skin friction, in the case of light fluid injection. The second aim is to estimate the Kolmogorov and large eddies' scales to construct LES grid to access instant variables in experience.
Journal of Renewable Energies, Oct 3, 2023
Journal of Renewable Energies
The three-dimensional numerical simulation of laminar mixed convection heat transfer with and wit... more The three-dimensional numerical simulation of laminar mixed convection heat transfer with and without porous medium in a cylindrical duct was carried out in this study. The cylinder is divided into three parts. The first and the third parts are adiabatic, while the central part is subjected to a constant heat flux. The effects of Darcy number, porosity, permeability and Nusselt number on heat transfer were considered. This problem is modeled by the Navier-stokes equations in the fluid region and by the Darcy-Brinkman-Forchheimer equation in the porous region, and for the thermal field the energy equation is used. The resolution of these equations was performed by the computational fluid dynamics code Ansys15.2 software using finite volume approach. The obtained results showed an accumulation of the hot fluid with stratification in the upper part of the pipe while the lower region of the pipe remained at practically constant temperature. The effect of the porous matrix is very notice...
L'utilisation des nouveaux techniques de l'injection permet d'améliorer les performan... more L'utilisation des nouveaux techniques de l'injection permet d'améliorer les performances de la combustion (stabilité, réduction des polluants, ...). Il est primordial de connaitre les caractéristiques de la combustion de ces combustibles hybrides dans différentes conditions, afin de pouvoir les utiliser d'une manière efficace dans les installations pratiques. L'approche expérimentale reste couteuse et limité certaines conditions opératoires. Cependant, le calcul numérique peut constituer la solution la plus adapté, compte tenu du progrès réalisé dans le domaine de l'informatique et de la modélisation. Dans ce contexte, les écoulements réactifs considérés sont complexes et dans un souci de validation, le couplage de LES/PDF doit montrer ses capacités sur des configurations non seulement académiques. Le but de cette th se est de d montrer le potentiel de ce couplage pour la pré diction des écoulements r actifs pauvre prémélangée et non-pré mélangée dans deux ty...
Energy Procedia, 2011
Our contribution consists of the demonstration of the advantages of LES-WALE coupled with PDF app... more Our contribution consists of the demonstration of the advantages of LES-WALE coupled with PDF approach including progress variable (c) in reacting flow, by using the Fluent-CFD. The confirmation is based on the comparison of three parameters: mean longitudinal velocity, intensity of longitudinal velocity and lengths of recirculations zones. In line with what was observed by the experimental reference study, the simulation succeeds to detect the flame zone of the recirculating region and shows the differences between the different cases of flows in variable equivalence ratio (and 0.75) or in variable mass flow rate (Q= 65 and 195 g/s). All cases of study considered the identical conditions from the tow supply channels of the burner. The main issue is the modeling of the closure of the turbulent combustion. In addition, the numerical simulation predicts as well as the asymmetry and the symmetry flow, respectively, for inert and reacting flows.
-Le présent travail est consacré à l'étude de la combustion turbulente non-prémélangée dans une c... more -Le présent travail est consacré à l'étude de la combustion turbulente non-prémélangée dans une chambre de combustion ayant une forme cylindrique avec deux jets coaxiaux (méthane/air). L'étude est basée sur l'approche de simulation numérique des grandes échelles turbulentes. L'aspect chimique de la combustion est traité par le modèle PDF. On a pu capté les zones importantes (flamme et recirculation) observées expérimentalement. Ce travail est orienté beaucoup plus à l'
Abstract- Non-premixed turbulent flames control many practical applications of combustion. Studyi... more Abstract- Non-premixed turbulent flames control many practical applications of combustion. Studying these mechanisms has been the objective of numerous theoretical and experimental works, numerical simulation is also widely used to understand these flames. A brief review of numerical models for non-premixed turbulent combustion is given. This research work focuses on the coupling of Beta-PDF approach with LES model. In this study, we deal with the flame evolution inside the combustion chamber, this would help in protecting the walls from being overheated and might damage. On the other hand, this work focuses on, CO production and conversion in the flame zone. The combustion system is modelled using Beta-PDF coupled with LES to predict the velocity field, CO mass fraction, and the temperature field. Our predictions are validated using the available experimental data. The new developed model succeeded in simulating the swirling and the flame zone. The results show a good agreement wit...
Understanding the behavior of laminar flow within microchannels is gaining more importance with t... more Understanding the behavior of laminar flow within microchannels is gaining more importance with the recent interest in microfluidics devices. In the current work, a numerical model was developed to evaluate the effect of surface roughness on hydrodynamic characteristics. In this model, the rough surface is configured with rectangular and triangular elements, respectively. Basing on the entropy production, an equation was developed to study the effect of the fluid flow on the Poiseuille number within valleys and within the reduced cross sections, separately. Also, the calculation of the entropy generation was used to understand the effect of roughness elements on Poiseuille number, and to predict a tendency to their variation with Reynolds number. As a result, a significant increase in Poiseuille number is detected for all configurations. It was detected that the Poiseuille number increases linearly with Reynolds, and this variation is mainly due to the fluid recirculation.
European Journal of Mechanical and Environmental Engineering, 2003
Les effets de différences de densité importantes sur les transferts turbulents en couche limite s... more Les effets de différences de densité importantes sur les transferts turbulents en couche limite sont étudiés expérimentalement. Les écarts de densité au sein de la couche limite sont produits par injection tangentielle d'air ou d'hélium dans un mélange de ces deux constituants. Les résultats montrent que la couche limite turbulente obtenue est associé à un gradient de densité normal à la paroi. Pour une vitesse d'injection donnée, les mesures mettent en évidence la conservation du frottement pariétal, et donc l'influence des différences de densité sur la vitesse de frottement. De plus, une forte corrélation entre les variations de densité et de vitesse montre l'influence marquée des structures cohérentes sur les phénomènes de transfert. Les résultats des données expérimentales des fluctuations de vitesse et de densité montrent que le développement spatio-temporel du flux massique turbulent longitudinal est fortement lié aux gradients de densité. La structure du flux massique turbulent ne dépend pas implicitement de la différence de densité mais plutôt de ses gradients. L'analyse dans les quadrants montre que l'injection d'hélium, dans la couche limite, engendre des éjections plus violentes que dans le cas d'une injection d'air. Ce résultat est confirmé par la contribution importante des éjections au flux massique turbulent.
Mathematical Modelling of Engineering Problems
The first objective of this numerical research is to help understand the influence of variable de... more The first objective of this numerical research is to help understand the influence of variable density on the structure of turbulence, through the study of a wall jet, and to validate our results with those of the experimental study of A. Soudani. The source of density variation is the mixture between two different non-reactive fluids, with a fixed temperature and pressure. A mass weighted averaging for different variables is applied to the calculation, using ANSYS FLUENT 15.0 commercial software. The principal experience consists of injecting tangentially and alternatively near the wall a gas (air-helium) different from the external flow, through a slot of height 3mm between two plane walls. Such a process permits to provoke an important density difference. The study reaches the conclusion that turbulence is strong, with a slight increase of velocity near the wall and an evident diminution of skin friction, in the case of light fluid injection. The second aim is to estimate the Kol...
Http Www Theses Fr, 1996
Une nouvelle methode pour le depouillement des etalonnages des sondes thermo-anemometriques a fil... more Une nouvelle methode pour le depouillement des etalonnages des sondes thermo-anemometriques a fil et film chauds, est employee pour les mesures simultanees de vitesses et de densite dans un ecoulement turbulent. La methode est fondee sur une application specifique des reseaux de neurones. Il s'agit de reseaux du type perceptron multicouches ayant pour regle d'apprentissage, l'algorithme de la retropogation d'erreur. Cette methode auto-adaptative a ete appliquee aux etalonnages de deux types de sonde. Elle donne une meilleure precision sur la reduction des etalonnages que les methodes classiques d'ajustement utilisant les regressions polynomiales. Les resultats obtenus par ce type de reseaux de neurones, pour le depouillement des mesures doubles simultanees, sont tres satisfaisants. Les comparaisons effectuees montre que la methode semble plus precise que celles utilisees habituellement. Les effets des differences de densite importantes, sur la structure fine de la turbulence parietale sont etudies a partir des donnees experimentales, obtenues dans une soufflerie a recirculation. Ces differences de densite, dans la couche limite, sont produites par injection tangentielle d'air ou d'helium dans un melange air-helium. Les resultats d'analyse des donnees experimentales des fluctuations de vitesse et de densite montrent que, le developpement spatio-temporel du flux massique turbulent longitudinal est fortement lie aux gradients de densite. La structure fine du flux massique turbulent ne depend pas implicitement de la difference de densite mais plutot de ses gradients. L'analyse conditionnelle dans les quadrants montre que l'injection d'helium, dans la couche limite, engendre des ejections plus violentes que dans le cas d'une injection d'air. Ce resultat est confirme par l'analyse statistique qui revele la contribution importante des ejections au flux massique turbulent
A three-dimensional numerical and asymptotic study of the steady laminar flow driven by a rotatin... more A three-dimensional numerical and asymptotic study of the steady laminar flow driven by a rotating lid at the top of an enclosed cylinder filled with a liquid metal and submitted to an axial magnetic B, is presented. The governing equations together with appropriate boundary conditions in the cylindrical coordinates (r,θ,z) are discretized by using a finite-volume method. Calculations were made
Journal of Applied Mechanics, 2012
This numerical investigation deals with the validation of the experimental results in the inert c... more This numerical investigation deals with the validation of the experimental results in the inert cases of Nguyen et al., obtained in the framework of the European Union-funded research program MOLECULES (Modelling of Low Emissions Combustors Using Large Eddy Simulations). This study is based on the benchmark of testing one rig for accurate comparisons with large eddy simulations configuration (ORACLES), aimed at helping the design of reliable lean premixed prevaporized) combustion chambers and supplied with two identical flows of air channels. Therefore, this study is based on the 3D numerical simulation using large eddy simulation-wall adapting local eddy viscosity (LES-WALE) model that aims to determine the longitudinal velocity, the longitudinal velocity fluctuation and the length of recirculation zone for the three cases of flow in different inlet Reynolds (Re = 25,000, 50,000, 75,000). Calculations are carried out by the FLUENT_CFD. The results obtained are compared with experim...
The majority of aerospace engines such as turboreactor and rocket engines work due to the process... more The majority of aerospace engines such as turboreactor and rocket engines work due to the process of combustion, which is also responsible for the formation of harmful and pollutants chemical species in the environment. The progress in engine technology asks constructors to respect the environmental regulations; this is required to develop ecological and cleaner engines. Our investigation was based on a configuration of cylindrical combustion chamber similar to the turboreactor, using the injection of methane and air with different inlet velocity, in order to calculate the temperature field and estimate the mass fraction of carbon monoxide (CO) at different region of the burner, using the solution of aerothermochemistry equations. The validation is based on experimental data of C.P. David (Sanford-USA. 2001).
Mecanique Industries, Nov 1, 2004
-Afin d'étudier la structure fine de la turbulence pariétale en présence de variations importante... more -Afin d'étudier la structure fine de la turbulence pariétale en présence de variations importantes de densité, une analyse statistique des données expérimentales, dans une soufflerieà recirculation, est effectuée. Les résultats montrent que la relaxation du facteur de dissymétrie de u (S u) s'effectue plus rapidement dans la couche externe que près de la paroi, aussi bien pour l'injection de l'air que pour l'injection d'hélium. S u croît près de la fente d'injection de façon appréciable et cette augmentation est nettement plus accentuée pour l'injection de l'air que l'injection d'hélium. Cette croissance du facteur de dissymétrie près de la fente d'injection peut s'expliquer par l'augmentation du flux convectif longitudinal de l'énergie turbulente dans cette zone. Les résultats montrent, pour la distribution du facteur d'aplatissement F u , qu'il n'y a pas d'effet important du gradient de densité sur la structure intermittente de la vitesse longitudinale instantanée dans la zone développée, x/δ ≥ 5. L'analyse statistique menée dans cetteétude montre que l'injection d'hélium, dans la couche limite, engendre deséjections plus violentes que dans le cas d'une injection d'air. Ce résultat est confirmé par la contribution importante deséjections au flux massique turbulent.
The Canadian Journal of Chemical Engineering, Feb 1, 2013
In comparison to previous numerical studies interested in the ORACLES benchmark (One Rig for Accu... more In comparison to previous numerical studies interested in the ORACLES benchmark (One Rig for Accurate Comparisons with Large Eddy Simulations), the present study demonstrates the advantages of LES-WALE model in both inert and reacting flows using the Fluent-CFD. So, the confirmation is based on the experimental research effort that was involved in the European Union-funded research program MOLECULES (Modelling of Low Emissions Combustors Using Large Eddy Simulations), for three parameters: longitudinal velocity, longitudinal velocity fluctuation, and length of recirculation zone. In line with what was observed by the experimental reference study, the dynamic model (LES-WALE) predicts, respectively, as well as the asymmetry and the symmetry, for both inert and reacting flows. In addition, the simulation succeeds to predict the zones of recirculation and shows the differences between the two cases, inert and reacting flows. Moreover, results have been compared with those of the k-ε model performed by Kurenkov and Obserlack [Kurenkov and Obserlack, Flow Turbulence Combustion 74, 387-407 (2005)] study.
Instrumentation Mesure Métrologie
This work is devoted to the study of heat transfer in a cubic chamber partially filled with a por... more This work is devoted to the study of heat transfer in a cubic chamber partially filled with a porous material by a single fluid. The mathematical model used is that of Darcy-Brinkman-Forchheimer. The modeled equations of continuity, motion, energy and mass are numerically solved by the finite volume method. The influence of permeability and other parameters on heat transfer has been studied. The results obtained show that Nusselt numbers increase with increasing permeability for different Darcy numbers, and decrease with increasing porous thickness. The numerical results of our study are in good agreement with those found in the literature.
Mathematical modelling of engineering problems, Aug 31, 2021
The first objective of this numerical research is to help understand the influence of variable de... more The first objective of this numerical research is to help understand the influence of variable density on the structure of turbulence, through the study of a wall jet, and to validate our results with those of the experimental study of A. Soudani. The source of density variation is the mixture between two different non-reactive fluids, with a fixed temperature and pressure. A mass weighted averaging for different variables is applied to the calculation, using ANSYS FLUENT 15.0 commercial software. The principal experience consists of injecting tangentially and alternatively near the wall a gas (airhelium) different from the external flow, through a slot of height 3mm between two plane walls. Such a process permits to provoke an important density difference. The study reaches the conclusion that turbulence is strong, with a slight increase of velocity near the wall and an evident diminution of skin friction, in the case of light fluid injection. The second aim is to estimate the Kolmogorov and large eddies' scales to construct LES grid to access instant variables in experience.
Journal of Renewable Energies, Oct 3, 2023
Journal of Renewable Energies
The three-dimensional numerical simulation of laminar mixed convection heat transfer with and wit... more The three-dimensional numerical simulation of laminar mixed convection heat transfer with and without porous medium in a cylindrical duct was carried out in this study. The cylinder is divided into three parts. The first and the third parts are adiabatic, while the central part is subjected to a constant heat flux. The effects of Darcy number, porosity, permeability and Nusselt number on heat transfer were considered. This problem is modeled by the Navier-stokes equations in the fluid region and by the Darcy-Brinkman-Forchheimer equation in the porous region, and for the thermal field the energy equation is used. The resolution of these equations was performed by the computational fluid dynamics code Ansys15.2 software using finite volume approach. The obtained results showed an accumulation of the hot fluid with stratification in the upper part of the pipe while the lower region of the pipe remained at practically constant temperature. The effect of the porous matrix is very notice...
L'utilisation des nouveaux techniques de l'injection permet d'améliorer les performan... more L'utilisation des nouveaux techniques de l'injection permet d'améliorer les performances de la combustion (stabilité, réduction des polluants, ...). Il est primordial de connaitre les caractéristiques de la combustion de ces combustibles hybrides dans différentes conditions, afin de pouvoir les utiliser d'une manière efficace dans les installations pratiques. L'approche expérimentale reste couteuse et limité certaines conditions opératoires. Cependant, le calcul numérique peut constituer la solution la plus adapté, compte tenu du progrès réalisé dans le domaine de l'informatique et de la modélisation. Dans ce contexte, les écoulements réactifs considérés sont complexes et dans un souci de validation, le couplage de LES/PDF doit montrer ses capacités sur des configurations non seulement académiques. Le but de cette th se est de d montrer le potentiel de ce couplage pour la pré diction des écoulements r actifs pauvre prémélangée et non-pré mélangée dans deux ty...
Energy Procedia, 2011
Our contribution consists of the demonstration of the advantages of LES-WALE coupled with PDF app... more Our contribution consists of the demonstration of the advantages of LES-WALE coupled with PDF approach including progress variable (c) in reacting flow, by using the Fluent-CFD. The confirmation is based on the comparison of three parameters: mean longitudinal velocity, intensity of longitudinal velocity and lengths of recirculations zones. In line with what was observed by the experimental reference study, the simulation succeeds to detect the flame zone of the recirculating region and shows the differences between the different cases of flows in variable equivalence ratio (and 0.75) or in variable mass flow rate (Q= 65 and 195 g/s). All cases of study considered the identical conditions from the tow supply channels of the burner. The main issue is the modeling of the closure of the turbulent combustion. In addition, the numerical simulation predicts as well as the asymmetry and the symmetry flow, respectively, for inert and reacting flows.
-Le présent travail est consacré à l'étude de la combustion turbulente non-prémélangée dans une c... more -Le présent travail est consacré à l'étude de la combustion turbulente non-prémélangée dans une chambre de combustion ayant une forme cylindrique avec deux jets coaxiaux (méthane/air). L'étude est basée sur l'approche de simulation numérique des grandes échelles turbulentes. L'aspect chimique de la combustion est traité par le modèle PDF. On a pu capté les zones importantes (flamme et recirculation) observées expérimentalement. Ce travail est orienté beaucoup plus à l'
Abstract- Non-premixed turbulent flames control many practical applications of combustion. Studyi... more Abstract- Non-premixed turbulent flames control many practical applications of combustion. Studying these mechanisms has been the objective of numerous theoretical and experimental works, numerical simulation is also widely used to understand these flames. A brief review of numerical models for non-premixed turbulent combustion is given. This research work focuses on the coupling of Beta-PDF approach with LES model. In this study, we deal with the flame evolution inside the combustion chamber, this would help in protecting the walls from being overheated and might damage. On the other hand, this work focuses on, CO production and conversion in the flame zone. The combustion system is modelled using Beta-PDF coupled with LES to predict the velocity field, CO mass fraction, and the temperature field. Our predictions are validated using the available experimental data. The new developed model succeeded in simulating the swirling and the flame zone. The results show a good agreement wit...
Understanding the behavior of laminar flow within microchannels is gaining more importance with t... more Understanding the behavior of laminar flow within microchannels is gaining more importance with the recent interest in microfluidics devices. In the current work, a numerical model was developed to evaluate the effect of surface roughness on hydrodynamic characteristics. In this model, the rough surface is configured with rectangular and triangular elements, respectively. Basing on the entropy production, an equation was developed to study the effect of the fluid flow on the Poiseuille number within valleys and within the reduced cross sections, separately. Also, the calculation of the entropy generation was used to understand the effect of roughness elements on Poiseuille number, and to predict a tendency to their variation with Reynolds number. As a result, a significant increase in Poiseuille number is detected for all configurations. It was detected that the Poiseuille number increases linearly with Reynolds, and this variation is mainly due to the fluid recirculation.
European Journal of Mechanical and Environmental Engineering, 2003
Les effets de différences de densité importantes sur les transferts turbulents en couche limite s... more Les effets de différences de densité importantes sur les transferts turbulents en couche limite sont étudiés expérimentalement. Les écarts de densité au sein de la couche limite sont produits par injection tangentielle d'air ou d'hélium dans un mélange de ces deux constituants. Les résultats montrent que la couche limite turbulente obtenue est associé à un gradient de densité normal à la paroi. Pour une vitesse d'injection donnée, les mesures mettent en évidence la conservation du frottement pariétal, et donc l'influence des différences de densité sur la vitesse de frottement. De plus, une forte corrélation entre les variations de densité et de vitesse montre l'influence marquée des structures cohérentes sur les phénomènes de transfert. Les résultats des données expérimentales des fluctuations de vitesse et de densité montrent que le développement spatio-temporel du flux massique turbulent longitudinal est fortement lié aux gradients de densité. La structure du flux massique turbulent ne dépend pas implicitement de la différence de densité mais plutôt de ses gradients. L'analyse dans les quadrants montre que l'injection d'hélium, dans la couche limite, engendre des éjections plus violentes que dans le cas d'une injection d'air. Ce résultat est confirmé par la contribution importante des éjections au flux massique turbulent.
Mathematical Modelling of Engineering Problems
The first objective of this numerical research is to help understand the influence of variable de... more The first objective of this numerical research is to help understand the influence of variable density on the structure of turbulence, through the study of a wall jet, and to validate our results with those of the experimental study of A. Soudani. The source of density variation is the mixture between two different non-reactive fluids, with a fixed temperature and pressure. A mass weighted averaging for different variables is applied to the calculation, using ANSYS FLUENT 15.0 commercial software. The principal experience consists of injecting tangentially and alternatively near the wall a gas (air-helium) different from the external flow, through a slot of height 3mm between two plane walls. Such a process permits to provoke an important density difference. The study reaches the conclusion that turbulence is strong, with a slight increase of velocity near the wall and an evident diminution of skin friction, in the case of light fluid injection. The second aim is to estimate the Kol...
Http Www Theses Fr, 1996
Une nouvelle methode pour le depouillement des etalonnages des sondes thermo-anemometriques a fil... more Une nouvelle methode pour le depouillement des etalonnages des sondes thermo-anemometriques a fil et film chauds, est employee pour les mesures simultanees de vitesses et de densite dans un ecoulement turbulent. La methode est fondee sur une application specifique des reseaux de neurones. Il s'agit de reseaux du type perceptron multicouches ayant pour regle d'apprentissage, l'algorithme de la retropogation d'erreur. Cette methode auto-adaptative a ete appliquee aux etalonnages de deux types de sonde. Elle donne une meilleure precision sur la reduction des etalonnages que les methodes classiques d'ajustement utilisant les regressions polynomiales. Les resultats obtenus par ce type de reseaux de neurones, pour le depouillement des mesures doubles simultanees, sont tres satisfaisants. Les comparaisons effectuees montre que la methode semble plus precise que celles utilisees habituellement. Les effets des differences de densite importantes, sur la structure fine de la turbulence parietale sont etudies a partir des donnees experimentales, obtenues dans une soufflerie a recirculation. Ces differences de densite, dans la couche limite, sont produites par injection tangentielle d'air ou d'helium dans un melange air-helium. Les resultats d'analyse des donnees experimentales des fluctuations de vitesse et de densite montrent que, le developpement spatio-temporel du flux massique turbulent longitudinal est fortement lie aux gradients de densite. La structure fine du flux massique turbulent ne depend pas implicitement de la difference de densite mais plutot de ses gradients. L'analyse conditionnelle dans les quadrants montre que l'injection d'helium, dans la couche limite, engendre des ejections plus violentes que dans le cas d'une injection d'air. Ce resultat est confirme par l'analyse statistique qui revele la contribution importante des ejections au flux massique turbulent
A three-dimensional numerical and asymptotic study of the steady laminar flow driven by a rotatin... more A three-dimensional numerical and asymptotic study of the steady laminar flow driven by a rotating lid at the top of an enclosed cylinder filled with a liquid metal and submitted to an axial magnetic B, is presented. The governing equations together with appropriate boundary conditions in the cylindrical coordinates (r,θ,z) are discretized by using a finite-volume method. Calculations were made
Journal of Applied Mechanics, 2012
This numerical investigation deals with the validation of the experimental results in the inert c... more This numerical investigation deals with the validation of the experimental results in the inert cases of Nguyen et al., obtained in the framework of the European Union-funded research program MOLECULES (Modelling of Low Emissions Combustors Using Large Eddy Simulations). This study is based on the benchmark of testing one rig for accurate comparisons with large eddy simulations configuration (ORACLES), aimed at helping the design of reliable lean premixed prevaporized) combustion chambers and supplied with two identical flows of air channels. Therefore, this study is based on the 3D numerical simulation using large eddy simulation-wall adapting local eddy viscosity (LES-WALE) model that aims to determine the longitudinal velocity, the longitudinal velocity fluctuation and the length of recirculation zone for the three cases of flow in different inlet Reynolds (Re = 25,000, 50,000, 75,000). Calculations are carried out by the FLUENT_CFD. The results obtained are compared with experim...
The majority of aerospace engines such as turboreactor and rocket engines work due to the process... more The majority of aerospace engines such as turboreactor and rocket engines work due to the process of combustion, which is also responsible for the formation of harmful and pollutants chemical species in the environment. The progress in engine technology asks constructors to respect the environmental regulations; this is required to develop ecological and cleaner engines. Our investigation was based on a configuration of cylindrical combustion chamber similar to the turboreactor, using the injection of methane and air with different inlet velocity, in order to calculate the temperature field and estimate the mass fraction of carbon monoxide (CO) at different region of the burner, using the solution of aerothermochemistry equations. The validation is based on experimental data of C.P. David (Sanford-USA. 2001).
Mecanique Industries, Nov 1, 2004
-Afin d'étudier la structure fine de la turbulence pariétale en présence de variations importante... more -Afin d'étudier la structure fine de la turbulence pariétale en présence de variations importantes de densité, une analyse statistique des données expérimentales, dans une soufflerieà recirculation, est effectuée. Les résultats montrent que la relaxation du facteur de dissymétrie de u (S u) s'effectue plus rapidement dans la couche externe que près de la paroi, aussi bien pour l'injection de l'air que pour l'injection d'hélium. S u croît près de la fente d'injection de façon appréciable et cette augmentation est nettement plus accentuée pour l'injection de l'air que l'injection d'hélium. Cette croissance du facteur de dissymétrie près de la fente d'injection peut s'expliquer par l'augmentation du flux convectif longitudinal de l'énergie turbulente dans cette zone. Les résultats montrent, pour la distribution du facteur d'aplatissement F u , qu'il n'y a pas d'effet important du gradient de densité sur la structure intermittente de la vitesse longitudinale instantanée dans la zone développée, x/δ ≥ 5. L'analyse statistique menée dans cetteétude montre que l'injection d'hélium, dans la couche limite, engendre deséjections plus violentes que dans le cas d'une injection d'air. Ce résultat est confirmé par la contribution importante deséjections au flux massique turbulent.
The Canadian Journal of Chemical Engineering, Feb 1, 2013
In comparison to previous numerical studies interested in the ORACLES benchmark (One Rig for Accu... more In comparison to previous numerical studies interested in the ORACLES benchmark (One Rig for Accurate Comparisons with Large Eddy Simulations), the present study demonstrates the advantages of LES-WALE model in both inert and reacting flows using the Fluent-CFD. So, the confirmation is based on the experimental research effort that was involved in the European Union-funded research program MOLECULES (Modelling of Low Emissions Combustors Using Large Eddy Simulations), for three parameters: longitudinal velocity, longitudinal velocity fluctuation, and length of recirculation zone. In line with what was observed by the experimental reference study, the dynamic model (LES-WALE) predicts, respectively, as well as the asymmetry and the symmetry, for both inert and reacting flows. In addition, the simulation succeeds to predict the zones of recirculation and shows the differences between the two cases, inert and reacting flows. Moreover, results have been compared with those of the k-ε model performed by Kurenkov and Obserlack [Kurenkov and Obserlack, Flow Turbulence Combustion 74, 387-407 (2005)] study.
Instrumentation Mesure Métrologie
This work is devoted to the study of heat transfer in a cubic chamber partially filled with a por... more This work is devoted to the study of heat transfer in a cubic chamber partially filled with a porous material by a single fluid. The mathematical model used is that of Darcy-Brinkman-Forchheimer. The modeled equations of continuity, motion, energy and mass are numerically solved by the finite volume method. The influence of permeability and other parameters on heat transfer has been studied. The results obtained show that Nusselt numbers increase with increasing permeability for different Darcy numbers, and decrease with increasing porous thickness. The numerical results of our study are in good agreement with those found in the literature.