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Partager le résultat de cette recherche Interroger des sources externesÉtude Numérique des écoulements thermoconvectifs d’un nanofluide à travers un espace cylindrique annulaire muni d’ailettes / Mohammed Benkhedda
Titre : Étude Numérique des écoulements thermoconvectifs d’un nanofluide à travers un espace cylindrique annulaire muni d’ailettes Type de document : texte imprimé Auteurs : Mohammed Benkhedda, Auteur ; Toufik Boufendi, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2018 Importance : 251 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
ChimieTags : Nanofluide Convection mixte Cylindre annulaire horizontal Monophasique Ailettes longitudinales Nanofluide hybride Volumes finis Nanofluid Mixed convection Horizontal annular cylinder Single phase longitudinal fins Hybrid nanofluid Finite volume ??? ????? ????? ??????? ?????? ??????? ????? ????? ????? ????? ???? ?????
???? ?????? ????????Index. décimale : 530 Physique Résumé : The doctoral project concerns a three-dimensional numerical study of the thermo-convective flows of a nanofluid through an annular cylindrical space without fin and equipped with fins. Newtonian, incompressible and laminar flow with temperature dependent physical properties. The single-phase approach is adopted. The outer cylinder is uniformly heated while the inner cylinder is adiabatic. The flow and thermal fields are modeled by the continuity equation, the three momentum equations and the energy equation of the nanofluid with appropriate initial and boundary conditions using a cylindrical coordinate system. The nonlinear differential equations with partial derivatives are solved numerically by the finite volume method with a spatio-temporal discretization of the second order. The SIMPLER algorithm was used to solve the speed-pressure coupling. A complete parametric analysis on the effect of the presence of nanoparticles dispersed in the fluid such as volume fraction, type and shape on the development of thermal and hydrodynamic fields. The dimensionless control parameters that control the problem under consideration are the Reynolds number, the Prandtl number and the Grashof number, a radius ratio set to 2. For the volume fraction ranging from 0 to 10%, six nanoparticles Types, two metallic types Cu and Ag, three ceramics Al2O3, TiO2 and CuO. Also four forms of the nanoparticles are the shape the spherical shape, Blade, Cylinder, Platelet and Bricks shape. The study of these effects on heat transfer in a annular cylinder without fins and with fins is the main objective of this study. The results concerning the different cases studied for the effect of the volume fraction of the different nanofluids shows that the increase in the volume fraction increases the heat transfer along the annular duct. The axial and mean Nusselt numbers obtained are also higher in the case of the nanofluid (Ag / water). They also show that the use of the Ag nanoparticle induces a better improvement of the heat transfer followed by Cu, Al2O3, CuO at the end TiO2. Regarding the effect of the shape of the nanoparticles Blade shape greatly improves the heat transfer compared to other shapes. A generating correlation expresses the average Nusselt number for the different shapes as a function of the volume fraction proposed: Nu moy = a + bϕ + cϕ2. Another correlation which expresses the average Nusselt number of the nanofluid (TiO2/water) and the hybrid nanofluid (Ag-TiO2 / water) as a function of the number of Grashof, Prandtl and the volume fraction: The use of the heat-generating fins, attached longitudinally to the outer cylinder and immersed in the nanofluid, greatly improves the heat transfer compared to those of a nonfinned horizontal duct dû to the increase in the exchange area between The nanofluid and the fins in the annular space.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/BOU7334.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10984 Étude Numérique des écoulements thermoconvectifs d’un nanofluide à travers un espace cylindrique annulaire muni d’ailettes [texte imprimé] / Mohammed Benkhedda, Auteur ; Toufik Boufendi, Directeur de thèse . - [S.l.] : جامعة الإخوة منتوري قسنطينة, 2018 . - 251 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
ChimieTags : Nanofluide Convection mixte Cylindre annulaire horizontal Monophasique Ailettes longitudinales Nanofluide hybride Volumes finis Nanofluid Mixed convection Horizontal annular cylinder Single phase longitudinal fins Hybrid nanofluid Finite volume ??? ????? ????? ??????? ?????? ??????? ????? ????? ????? ????? ???? ?????
???? ?????? ????????Index. décimale : 530 Physique Résumé : The doctoral project concerns a three-dimensional numerical study of the thermo-convective flows of a nanofluid through an annular cylindrical space without fin and equipped with fins. Newtonian, incompressible and laminar flow with temperature dependent physical properties. The single-phase approach is adopted. The outer cylinder is uniformly heated while the inner cylinder is adiabatic. The flow and thermal fields are modeled by the continuity equation, the three momentum equations and the energy equation of the nanofluid with appropriate initial and boundary conditions using a cylindrical coordinate system. The nonlinear differential equations with partial derivatives are solved numerically by the finite volume method with a spatio-temporal discretization of the second order. The SIMPLER algorithm was used to solve the speed-pressure coupling. A complete parametric analysis on the effect of the presence of nanoparticles dispersed in the fluid such as volume fraction, type and shape on the development of thermal and hydrodynamic fields. The dimensionless control parameters that control the problem under consideration are the Reynolds number, the Prandtl number and the Grashof number, a radius ratio set to 2. For the volume fraction ranging from 0 to 10%, six nanoparticles Types, two metallic types Cu and Ag, three ceramics Al2O3, TiO2 and CuO. Also four forms of the nanoparticles are the shape the spherical shape, Blade, Cylinder, Platelet and Bricks shape. The study of these effects on heat transfer in a annular cylinder without fins and with fins is the main objective of this study. The results concerning the different cases studied for the effect of the volume fraction of the different nanofluids shows that the increase in the volume fraction increases the heat transfer along the annular duct. The axial and mean Nusselt numbers obtained are also higher in the case of the nanofluid (Ag / water). They also show that the use of the Ag nanoparticle induces a better improvement of the heat transfer followed by Cu, Al2O3, CuO at the end TiO2. Regarding the effect of the shape of the nanoparticles Blade shape greatly improves the heat transfer compared to other shapes. A generating correlation expresses the average Nusselt number for the different shapes as a function of the volume fraction proposed: Nu moy = a + bϕ + cϕ2. Another correlation which expresses the average Nusselt number of the nanofluid (TiO2/water) and the hybrid nanofluid (Ag-TiO2 / water) as a function of the number of Grashof, Prandtl and the volume fraction: The use of the heat-generating fins, attached longitudinally to the outer cylinder and immersed in the nanofluid, greatly improves the heat transfer compared to those of a nonfinned horizontal duct dû to the increase in the exchange area between The nanofluid and the fins in the annular space.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/BOU7334.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10984 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BEN/7334 BEN/7334 Thèse Bibliothèque principale Thèses Disponible
Titre : Etude de la convection mixte dans des cavités. Type de document : texte imprimé Auteurs : Ilhem Zeghbid, Auteur ; R. Bessaih, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2017 Importance : 172 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
Génie MécaniqueTags : Mixed convection Cavities Entropy generation Nanofluid Convection mixte Cavités Génération d’entropie Nanofluide ???? ????? ????? ??????? ????? ?????? Index. décimale : 620 Génie Mécanique Résumé : The aim of this work is to study numerically the laminar mixed convection and
entropy generation in cavities. The calculations were performed for water (Cu, Ag)
metallic nanofluids and water-(AlO3, TiO2) metal oxides. The fluids are supposed
incompressible and Newtonian. The equations governing the flow and heat transfer have
been solved using the finite volume method. A house code in FORTRAN has been
developed to calculate the flow and temperature fields, the Nusselt number, and the
entropy generation. The effects of Rayleigh and Reynolds numbers , the volume fraction
of the nanofluid, the nanofluid type, and the position of the heat sources on the flow and
thermal fields, the average Nusselt number, entropy generation, and the Bejan number
are studied in detail. The results show that the use of nanofluids improves heat transfer
and reduces the entropy generation. Finally, a three-dimensional numerical study of
laminar forced convection in a cubic cavity filled with different nanofluids is presented.
In this study, the Ansys-Fluent 14 software was used to solve the equations of the
problem in questionDiplôme : Doctorat en sciences En ligne : ../theses/gmecanique/ZEG7096.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10508 Etude de la convection mixte dans des cavités. [texte imprimé] / Ilhem Zeghbid, Auteur ; R. Bessaih, Directeur de thèse . - [S.l.] : جامعة الإخوة منتوري قسنطينة, 2017 . - 172 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
Génie MécaniqueTags : Mixed convection Cavities Entropy generation Nanofluid Convection mixte Cavités Génération d’entropie Nanofluide ???? ????? ????? ??????? ????? ?????? Index. décimale : 620 Génie Mécanique Résumé : The aim of this work is to study numerically the laminar mixed convection and
entropy generation in cavities. The calculations were performed for water (Cu, Ag)
metallic nanofluids and water-(AlO3, TiO2) metal oxides. The fluids are supposed
incompressible and Newtonian. The equations governing the flow and heat transfer have
been solved using the finite volume method. A house code in FORTRAN has been
developed to calculate the flow and temperature fields, the Nusselt number, and the
entropy generation. The effects of Rayleigh and Reynolds numbers , the volume fraction
of the nanofluid, the nanofluid type, and the position of the heat sources on the flow and
thermal fields, the average Nusselt number, entropy generation, and the Bejan number
are studied in detail. The results show that the use of nanofluids improves heat transfer
and reduces the entropy generation. Finally, a three-dimensional numerical study of
laminar forced convection in a cubic cavity filled with different nanofluids is presented.
In this study, the Ansys-Fluent 14 software was used to solve the equations of the
problem in questionDiplôme : Doctorat en sciences En ligne : ../theses/gmecanique/ZEG7096.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10508 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité ZEG/7096 ZEG/7096 Thèse Bibliothèque principale Thèses Disponible
Titre : Étude Numérique de la Convection Mixte dans un Canal Horizontal Contenant des Ailettes Type de document : texte imprimé Auteurs : Moussa Khentoul, Auteur ; R. Bessaih, Auteur Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2016 Importance : 131 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
Génie MécaniqueTags : Convection mixte Canal horizontal Refroidissement nanofluide Ailettes Mixed convection horizontal channel Cooling nanofluid fins ????? ??????? ???? ????? ????? ???? ??????? ???????? Index. décimale : 620 Génie Mécanique Résumé : Heat transfer is very important for good design and reliable operation of a system.
Reliability and system performance are highly dependent on the operating temperature,
in particular, in electronic equipment. Several cooling methods have been proposed in
order to improve the heat transfer. These techniques include two: which consists in
grafting blades offering a greater contact surface with the environment; and which
consists of using nanofluids comprising metallic particles or carbon nanotubes. The
latter is currently present the best solution.
In the first part of the thesis, a numerical study of 2D laminar mixed convection in
a horizontal channel with three fins nanofluid has been carried out made. The influence
of Reynolds and Richardson numbers and concentration of nanoparticles (Al2O3, Cu, Ag
and TiO2) dispersed in a base fluid (water), on the flow and thermal fields is presented.
A computer code in Fortran, based on finite volume method was used to simulate 2D
flow with heat transfer. The results indicate that the addition of nanoparticles in pure
water can improve the cooling performance, in particular, low Richardson number. The
influence of the solid volume fraction on increasing the heat transfer is more sensitive to
higher values of Reynolds number. Although, the addition of nanofluids (TiO2 and
Al
2O3) also increases heat transfer, their influence is not important for Cu-Ag-water and
water.
The second part is to find an optimal geometry for good cooling. Numerical
calculations were carried out using the software ""FLUENT 6.3"" to simulate 3D laminar
mixed convection flow in a channel containing fins with nanofluid. The effects of
Reynolds number, height, and distance between the fins are presented and discussed.
Diplôme : Doctorat En ligne : ../theses/gmecanique/KHE6947.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10324 Étude Numérique de la Convection Mixte dans un Canal Horizontal Contenant des Ailettes [texte imprimé] / Moussa Khentoul, Auteur ; R. Bessaih, Auteur . - [S.l.] : جامعة الإخوة منتوري قسنطينة, 2016 . - 131 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
Génie MécaniqueTags : Convection mixte Canal horizontal Refroidissement nanofluide Ailettes Mixed convection horizontal channel Cooling nanofluid fins ????? ??????? ???? ????? ????? ???? ??????? ???????? Index. décimale : 620 Génie Mécanique Résumé : Heat transfer is very important for good design and reliable operation of a system.
Reliability and system performance are highly dependent on the operating temperature,
in particular, in electronic equipment. Several cooling methods have been proposed in
order to improve the heat transfer. These techniques include two: which consists in
grafting blades offering a greater contact surface with the environment; and which
consists of using nanofluids comprising metallic particles or carbon nanotubes. The
latter is currently present the best solution.
In the first part of the thesis, a numerical study of 2D laminar mixed convection in
a horizontal channel with three fins nanofluid has been carried out made. The influence
of Reynolds and Richardson numbers and concentration of nanoparticles (Al2O3, Cu, Ag
and TiO2) dispersed in a base fluid (water), on the flow and thermal fields is presented.
A computer code in Fortran, based on finite volume method was used to simulate 2D
flow with heat transfer. The results indicate that the addition of nanoparticles in pure
water can improve the cooling performance, in particular, low Richardson number. The
influence of the solid volume fraction on increasing the heat transfer is more sensitive to
higher values of Reynolds number. Although, the addition of nanofluids (TiO2 and
Al
2O3) also increases heat transfer, their influence is not important for Cu-Ag-water and
water.
The second part is to find an optimal geometry for good cooling. Numerical
calculations were carried out using the software ""FLUENT 6.3"" to simulate 3D laminar
mixed convection flow in a channel containing fins with nanofluid. The effects of
Reynolds number, height, and distance between the fins are presented and discussed.
Diplôme : Doctorat En ligne : ../theses/gmecanique/KHE6947.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10324 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité KHE/6947 KHE/6947 Thèse Bibliothèque principale Thèses Disponible
Titre : Génération d’entropie due au refroidissement par convection naturelle d’un nanofluide Type de document : texte imprimé Auteurs : Abd el malik Bouchoucha, Auteur ; Rachid Bessaih, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2017 Importance : 159 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
Génie MécaniqueTags : Nanofluide Génération d’entropie Convection naturelle Cavité Nanofluid Entropy generation Natural convection Cavity ????? ?????? ????? ? ???????? ????? ??????? ??????? ???? Index. décimale : 620 Génie Mécanique Résumé : Venous thromboembolism (VTE) is a multifactorial disease in which the genetic
component is important.Many genetic risk factors have been identified for causing VTE.
Most of them affect the function of natural anticoagulant pathways, particularly the prote
Diplôme : Doctorat En ligne : ../theses/gmecanique/BOU7046.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10553 Génération d’entropie due au refroidissement par convection naturelle d’un nanofluide [texte imprimé] / Abd el malik Bouchoucha, Auteur ; Rachid Bessaih, Directeur de thèse . - [S.l.] : جامعة الإخوة منتوري قسنطينة, 2017 . - 159 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
Génie MécaniqueTags : Nanofluide Génération d’entropie Convection naturelle Cavité Nanofluid Entropy generation Natural convection Cavity ????? ?????? ????? ? ???????? ????? ??????? ??????? ???? Index. décimale : 620 Génie Mécanique Résumé : Venous thromboembolism (VTE) is a multifactorial disease in which the genetic
component is important.Many genetic risk factors have been identified for causing VTE.
Most of them affect the function of natural anticoagulant pathways, particularly the prote
Diplôme : Doctorat En ligne : ../theses/gmecanique/BOU7046.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10553 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BOU/7046 BOU/7046 Thèse Bibliothèque principale Thèses Disponible
Titre : Etude numérique des transferts thermiques convectifs avec nano-fluides. Type de document : texte imprimé Auteurs : Esma Belahmadi, Auteur ; Rachid Bessaih, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2018 Importance : 148 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
Génie MécaniqueTags : Transfert de chaleur convectif Nanofluide Génération d’entropie Convective heat transfer Nanofluid Entropy generation ??? ????? ????? ??????? ??????????? (Nanofluide) ????? ????????? Index. décimale : 620 Génie Mécanique Résumé : In this work, we present the study of convective heat transfers with nanofluid and entropy generation inside three selected configurations. Two computational codes (AnsysFluent 14 and house-Fortran) were used to solve the partial differential equations describing natural convection and mixed laminar flows. Numerical results obtained by these codes were validated with those found in the literature, and a good agreement was obtained. The study presented in this thesis is divided into three parts.
The first part of this study is devoted to two-dimensional flow in a vertical channel with parallel plates traversed by a Cu-water nanofluid. The effects of Reynolds and Grashof numbers, and the nanofluid solid volume fraction on heat transfer and entropy generation are examined in detail. The results show that increasing the nanoparticle volume fraction and dimensionless numbers (Re, Gr) improves the heat transfer rate and decreases the
entropy generation in the channel.
The second part presents the axisymmetric flow of an Al2O3-water nanofluid between two vertical coaxial cylinders. The effects of Rayleigh, Hartmann numbers, inclination angle and solid volume fraction of nanoparticles on heat transfer and entropy generation are studied in detail. Results reveal that the heat transfer and entropy generation rates depend on the intensity and orientation of the magnetic field. In addition,
in all cases, the average Nusselt number and the total entropy generation increase by increasing the Rayleigh number and the volume fraction of nanoparticles.
The third part is based on heat transfer, stready state, in a horizontal cylindrical duct, traversed by a three-dimensional flow of a nanofluid subjected to a heat flux to the wall. The effects of Richardson and Hartmann numbers, solid volume fraction of the nanofluid, and the direction of the magnetic field on heat transfer and entropy generation are examined in detail. The results indicate that the heat transfer and entropy generation
rates depend on the intensity and direction of the magnetic field. In addition, the increase in the number of Richardson and the volume fraction of nanoparticles increases heat transfer and entropy generation. Finally, the application of a radial magnetic field promotes a better convective heat exchange and minimizes the entropy generation.
Diplôme : Doctorat en sciences En ligne : ../theses/gmecanique/BEL7268.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10886 Etude numérique des transferts thermiques convectifs avec nano-fluides. [texte imprimé] / Esma Belahmadi, Auteur ; Rachid Bessaih, Directeur de thèse . - [S.l.] : جامعة الإخوة منتوري قسنطينة, 2018 . - 148 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
Génie MécaniqueTags : Transfert de chaleur convectif Nanofluide Génération d’entropie Convective heat transfer Nanofluid Entropy generation ??? ????? ????? ??????? ??????????? (Nanofluide) ????? ????????? Index. décimale : 620 Génie Mécanique Résumé : In this work, we present the study of convective heat transfers with nanofluid and entropy generation inside three selected configurations. Two computational codes (AnsysFluent 14 and house-Fortran) were used to solve the partial differential equations describing natural convection and mixed laminar flows. Numerical results obtained by these codes were validated with those found in the literature, and a good agreement was obtained. The study presented in this thesis is divided into three parts.
The first part of this study is devoted to two-dimensional flow in a vertical channel with parallel plates traversed by a Cu-water nanofluid. The effects of Reynolds and Grashof numbers, and the nanofluid solid volume fraction on heat transfer and entropy generation are examined in detail. The results show that increasing the nanoparticle volume fraction and dimensionless numbers (Re, Gr) improves the heat transfer rate and decreases the
entropy generation in the channel.
The second part presents the axisymmetric flow of an Al2O3-water nanofluid between two vertical coaxial cylinders. The effects of Rayleigh, Hartmann numbers, inclination angle and solid volume fraction of nanoparticles on heat transfer and entropy generation are studied in detail. Results reveal that the heat transfer and entropy generation rates depend on the intensity and orientation of the magnetic field. In addition,
in all cases, the average Nusselt number and the total entropy generation increase by increasing the Rayleigh number and the volume fraction of nanoparticles.
The third part is based on heat transfer, stready state, in a horizontal cylindrical duct, traversed by a three-dimensional flow of a nanofluid subjected to a heat flux to the wall. The effects of Richardson and Hartmann numbers, solid volume fraction of the nanofluid, and the direction of the magnetic field on heat transfer and entropy generation are examined in detail. The results indicate that the heat transfer and entropy generation
rates depend on the intensity and direction of the magnetic field. In addition, the increase in the number of Richardson and the volume fraction of nanoparticles increases heat transfer and entropy generation. Finally, the application of a radial magnetic field promotes a better convective heat exchange and minimizes the entropy generation.
Diplôme : Doctorat en sciences En ligne : ../theses/gmecanique/BEL7268.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10886 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BEL/7268 BEL/7268 Thèse Bibliothèque principale Thèses Disponible
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