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Auteur Mahfoud Djezzar |
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Affiner la recherche Interroger des sources externesApproche numérique de la convection naturelle thermo-solutale dans une cavité rectangulaire poreuse saturée de fluide et à orientation variable. / Abdelhakim Latreche
Titre : Approche numérique de la convection naturelle thermo-solutale dans une cavité rectangulaire poreuse saturée de fluide et à orientation variable. Type de document : texte imprimé Auteurs : Abdelhakim Latreche, Auteur ; Mahfoud Djezzar, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2019 Importance : 101 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles Langues : Français (fre) Catégories : Français - Anglais
PhysiqueTags : Physique Energétique: Photothermique Transfert de chaleur et de masse milieux poreux convection naturelle Double
diffusion modèle de Darcy-Brinkmann-Forchheimer volumes finis Heat and mass transfer porous media natural convection Double diffusion Darcy-Brinkmann-Forchheimer model finite volumes انتقال الحرارة والكتلة الوسائط المسامية الحمل الحراري الانتشار المزدوج نموذج دارسي
برينكمان-فورخايمر الحجوم المتناهيةIndex. décimale : 530 Physique Résumé :
In this thesis, heat and mass transfers by natural convection in porous media have been studied numerically. The horizontal walls are subjected to constant temperatures and impermeable to solute transport in the first case and at constant temperatures and
concentrations in the second case, while the vertical walls are thermally insulated and are subjected to constant concentrations in the first case, and are considered adiabatic in the second case. The phenomenon of thermo-solutal convection is governed by the conservation equations of mass, momentum, energy and concentration. The porous media are modeled according to the general model of Darcy and Darcy-Brinkman-Forchheimer respectively. The convective flow is governed by different control parameters, namely the angle of inclination (α ), the Rayleigh number (Ra), the ratio of the forces of volume (N), the number of Prandtl (Pr),the number of Lewis (Le), the Darcy number (Da) the form factor (A) and the porosity ε of the porous matrix. The finite volume method was used to solve the basic equations in porous media. Regarding the validation of the calculation code, the agreement obtained between our results and those available in the literature proved to be excellent. The influence of physical and geometrical parameters is examined. In the first case, five solutions characterized by multicellular and single-cell clockwise / counterclockwise, natural / antinatural flows were obtained in the case of the intermediate regime with the variation of the inclination, the structure of the flow intensifies and the transfers of Heat and average mass increase as │N│ increases. In the second case, two solutions characterized by multicellular (-90° ≤α≤0°) and single-cell trigonometric (0°<α≤90°) flows were obtained, the intensity of the flow decreases with increasing of α in both directions, while there was an increase in heat transfer and mass up to inclination 45° and 60° respectively. The structure of the flow intensifies and the average heat and mass transfers increase with the increase of N, Ra and A while the contrary has been found with Le except the mass transfer which keeps its increase.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/LAT7514.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11353 Approche numérique de la convection naturelle thermo-solutale dans une cavité rectangulaire poreuse saturée de fluide et à orientation variable. [texte imprimé] / Abdelhakim Latreche, Auteur ; Mahfoud Djezzar, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2019 . - 101 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : Physique Energétique: Photothermique Transfert de chaleur et de masse milieux poreux convection naturelle Double
diffusion modèle de Darcy-Brinkmann-Forchheimer volumes finis Heat and mass transfer porous media natural convection Double diffusion Darcy-Brinkmann-Forchheimer model finite volumes انتقال الحرارة والكتلة الوسائط المسامية الحمل الحراري الانتشار المزدوج نموذج دارسي
برينكمان-فورخايمر الحجوم المتناهيةIndex. décimale : 530 Physique Résumé :
In this thesis, heat and mass transfers by natural convection in porous media have been studied numerically. The horizontal walls are subjected to constant temperatures and impermeable to solute transport in the first case and at constant temperatures and
concentrations in the second case, while the vertical walls are thermally insulated and are subjected to constant concentrations in the first case, and are considered adiabatic in the second case. The phenomenon of thermo-solutal convection is governed by the conservation equations of mass, momentum, energy and concentration. The porous media are modeled according to the general model of Darcy and Darcy-Brinkman-Forchheimer respectively. The convective flow is governed by different control parameters, namely the angle of inclination (α ), the Rayleigh number (Ra), the ratio of the forces of volume (N), the number of Prandtl (Pr),the number of Lewis (Le), the Darcy number (Da) the form factor (A) and the porosity ε of the porous matrix. The finite volume method was used to solve the basic equations in porous media. Regarding the validation of the calculation code, the agreement obtained between our results and those available in the literature proved to be excellent. The influence of physical and geometrical parameters is examined. In the first case, five solutions characterized by multicellular and single-cell clockwise / counterclockwise, natural / antinatural flows were obtained in the case of the intermediate regime with the variation of the inclination, the structure of the flow intensifies and the transfers of Heat and average mass increase as │N│ increases. In the second case, two solutions characterized by multicellular (-90° ≤α≤0°) and single-cell trigonometric (0°<α≤90°) flows were obtained, the intensity of the flow decreases with increasing of α in both directions, while there was an increase in heat transfer and mass up to inclination 45° and 60° respectively. The structure of the flow intensifies and the average heat and mass transfers increase with the increase of N, Ra and A while the contrary has been found with Le except the mass transfer which keeps its increase.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/LAT7514.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11353 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité LAT/7514 LAT/7514 Thèse Bibliothèque principale Thèses Disponible
Titre : Approche numerique de la convection naturelle thermosolutale dans des enceintes fermees Type de document : texte imprimé Auteurs : Chahinez Ghernouz, Auteur ; Mahfoud Djezzar, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2017 Importance : 91 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
PhysiqueTags : convection naturelle thermosolutale équations de Boussinesq espaces annulaires enceintes fermées Formulation vorticité-fonction de courant coordonnées bicylindriques thermosolutal natural convection Boussinesq equations annular space closed
enclosures vorticity-stream function formulation bicylindrical coordinates الحمل الطبيعي الحراري المادي معادلات بوسينسك فضاءات حلقية طريقة الحجوم المنتهية تجويفات مغلقةIndex. décimale : 530 Physique Résumé : The problem related to thermosolutal natural laminar and permanent convection
in horizontal annulus situated between two eccentric cylinders filled with Newtonian and
incompressible binary fluid oriented at an arbitrary angle is examined numerically. The
inner cylinder is heated with hot temperature T1 and high concentration S1 while the outer
cylinder is maintained at a cold constant temperature T2 and low concentration S2. The fluid
is air and the substance diffused in the enclosure is the vapor. The flow is driven by the
thermal and solutal buoyancies. The annular space is filled by a Newtonian and
incompressible fluid. The number of Prandtl is fixed at (0.71) but the thermal Rayleigh
number, the Lewis number, the slope angle, the relative eccentricity and the buoyancy ratio
vary. By using the approximation of Boussinesq and the vorticity-stream function
formulation, the flow is modeled by the differential equations with the derivative partial: the
equations of continuity, the momentum, the energy and mass are expressed in a frame of
reference known as "bicylindrical", to facilitate the writing of the boundary conditions and to
transform the curvilinear field into a rectangular one. A computer code was developed, the
latter uses finished volumes, for the discretization of the equations and in order to show its
reliability, the authors compare results resulting from the latter with other similar results
existing in the literature and they examine the effects of the slope of the system, of the relative
eccentricity, of the thermal Rayleigh number, of the Lewis number and of the buoyancy ratio
values on the results obtained that it is qualitatively or quantitatively.Diplôme : Doctorat en sciences En ligne : ../theses/physique/GHE7021.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10575 Approche numerique de la convection naturelle thermosolutale dans des enceintes fermees [texte imprimé] / Chahinez Ghernouz, Auteur ; Mahfoud Djezzar, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2017 . - 91 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : convection naturelle thermosolutale équations de Boussinesq espaces annulaires enceintes fermées Formulation vorticité-fonction de courant coordonnées bicylindriques thermosolutal natural convection Boussinesq equations annular space closed
enclosures vorticity-stream function formulation bicylindrical coordinates الحمل الطبيعي الحراري المادي معادلات بوسينسك فضاءات حلقية طريقة الحجوم المنتهية تجويفات مغلقةIndex. décimale : 530 Physique Résumé : The problem related to thermosolutal natural laminar and permanent convection
in horizontal annulus situated between two eccentric cylinders filled with Newtonian and
incompressible binary fluid oriented at an arbitrary angle is examined numerically. The
inner cylinder is heated with hot temperature T1 and high concentration S1 while the outer
cylinder is maintained at a cold constant temperature T2 and low concentration S2. The fluid
is air and the substance diffused in the enclosure is the vapor. The flow is driven by the
thermal and solutal buoyancies. The annular space is filled by a Newtonian and
incompressible fluid. The number of Prandtl is fixed at (0.71) but the thermal Rayleigh
number, the Lewis number, the slope angle, the relative eccentricity and the buoyancy ratio
vary. By using the approximation of Boussinesq and the vorticity-stream function
formulation, the flow is modeled by the differential equations with the derivative partial: the
equations of continuity, the momentum, the energy and mass are expressed in a frame of
reference known as "bicylindrical", to facilitate the writing of the boundary conditions and to
transform the curvilinear field into a rectangular one. A computer code was developed, the
latter uses finished volumes, for the discretization of the equations and in order to show its
reliability, the authors compare results resulting from the latter with other similar results
existing in the literature and they examine the effects of the slope of the system, of the relative
eccentricity, of the thermal Rayleigh number, of the Lewis number and of the buoyancy ratio
values on the results obtained that it is qualitatively or quantitatively.Diplôme : Doctorat en sciences En ligne : ../theses/physique/GHE7021.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10575 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité GHE/7021 GHE/7021 Thèse Bibliothèque principale Thèses Disponible
Titre : Contribution à l'étude de la convection naturelle dans differents espaces annulaires elliptiques confocaux, soumis à differentes conditions de chauffage Type de document : texte imprimé Auteurs : Mahfoud Djezzar ; Univ. de Constantine, Éditeur scientifique ; Michel Daguenet, Directeur de thèse Année de publication : 2005 Importance : 95 f. Note générale : 01 Disponible à la salle de recherche 02 Disponibles au magazin de la bibliothèque centrale 01 CD Langues : Français (fre) Catégories : Français - Anglais
PhysiqueTags : Convection naturelle Equation de Boussinesq Espaces annulaires Cylindres élliptiques Formulation vitesse-pression Index. décimale : 530 Physique Diplôme : Doctorat En ligne : ../theses/physique/DJE4352.pdf Permalink : index.php?lvl=notice_display&id=3603 Contribution à l'étude de la convection naturelle dans differents espaces annulaires elliptiques confocaux, soumis à differentes conditions de chauffage [texte imprimé] / Mahfoud Djezzar ; Univ. de Constantine, Éditeur scientifique ; Michel Daguenet, Directeur de thèse . - 2005 . - 95 f.
01 Disponible à la salle de recherche 02 Disponibles au magazin de la bibliothèque centrale 01 CD
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : Convection naturelle Equation de Boussinesq Espaces annulaires Cylindres élliptiques Formulation vitesse-pression Index. décimale : 530 Physique Diplôme : Doctorat En ligne : ../theses/physique/DJE4352.pdf Permalink : index.php?lvl=notice_display&id=3603 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité DJE/4352 DJE/4352 Thèse Bibliothèque principale Thèses Disponible
Titre : Contribution à l’étude de la convection naturelle dans des enceintes à parois courbées remplies de nanofluides. Type de document : texte imprimé Auteurs : Abdelaziz Yahiaoui, Auteur ; Mahfoud Djezzar, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2019 Importance : 147 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
PhysiqueTags : Physique Energétique: Photothermique convection naturelle nanofluides enceintes à parois courbées vorticité-fonction
de courant simulation numérique Natural convection Nanofluids enclosures with curved walls vorticity-Streamlines Numerical simulation الحمل الطبيعي النانوفلويد تجويف بجدران منحنية التدويم-دوال التيارات المحاكات العدديةIndex. décimale : 540 Chimie et sciences connexes Résumé :
In our investigation we have studied and compared the laminar and permanent natural convection in two-dimensional enclosures (square enclosure, enclosures with curved walls) filled with nanofluid (water-Cu) and subject to three different types of boundary conditions that are: first case (horizontal walls of enclosure are adiabatic, and vertical walls are isothermal maintained at cold temperature Tc and hot temperature Th), second case (vertical walls of enclosures are maintained isothermal at a cold temperature Tc, horizontal top walls are considered adiabatic and bottom walls are maintained isothermal at a constant hot temperature Th), third case (vertical walls of the enclosures are maintained isothermal at a cold temperature Tc, horizontal top walls are considered adiabatic and bottom walls are maintained at a sinusoidal hot temperature). We considered a Newtonian fluid and the flow is incompressible. The values of Rayleigh number are: 103, 104, 105 and 106, the Prandtl number is fixed to 6.2 and the volume fraction ϕ is taken equal to: 0, 0.1 and 0.2. The method used in this study is the finite volume method. The numerical results obtained show that the heat transfer rate increases both with increasing the volume fraction and the Rayleigh number, and that the average Nusselt number and therefore the heat transfer increases with the increase of the volume fraction of the nanoparticles for the full range of Rayleigh numbers, and that the effect of the nanofluid on natural convection is much more manifest for higher values of Rayleigh number.Note de contenu :
Annexes.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/YAH7521.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11360 Contribution à l’étude de la convection naturelle dans des enceintes à parois courbées remplies de nanofluides. [texte imprimé] / Abdelaziz Yahiaoui, Auteur ; Mahfoud Djezzar, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2019 . - 147 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : Physique Energétique: Photothermique convection naturelle nanofluides enceintes à parois courbées vorticité-fonction
de courant simulation numérique Natural convection Nanofluids enclosures with curved walls vorticity-Streamlines Numerical simulation الحمل الطبيعي النانوفلويد تجويف بجدران منحنية التدويم-دوال التيارات المحاكات العدديةIndex. décimale : 540 Chimie et sciences connexes Résumé :
In our investigation we have studied and compared the laminar and permanent natural convection in two-dimensional enclosures (square enclosure, enclosures with curved walls) filled with nanofluid (water-Cu) and subject to three different types of boundary conditions that are: first case (horizontal walls of enclosure are adiabatic, and vertical walls are isothermal maintained at cold temperature Tc and hot temperature Th), second case (vertical walls of enclosures are maintained isothermal at a cold temperature Tc, horizontal top walls are considered adiabatic and bottom walls are maintained isothermal at a constant hot temperature Th), third case (vertical walls of the enclosures are maintained isothermal at a cold temperature Tc, horizontal top walls are considered adiabatic and bottom walls are maintained at a sinusoidal hot temperature). We considered a Newtonian fluid and the flow is incompressible. The values of Rayleigh number are: 103, 104, 105 and 106, the Prandtl number is fixed to 6.2 and the volume fraction ϕ is taken equal to: 0, 0.1 and 0.2. The method used in this study is the finite volume method. The numerical results obtained show that the heat transfer rate increases both with increasing the volume fraction and the Rayleigh number, and that the average Nusselt number and therefore the heat transfer increases with the increase of the volume fraction of the nanoparticles for the full range of Rayleigh numbers, and that the effect of the nanofluid on natural convection is much more manifest for higher values of Rayleigh number.Note de contenu :
Annexes.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/YAH7521.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11360 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité YAH/7521 YAH/7521 Thèse Bibliothèque principale Thèses Disponible
Titre : Contribution à l’étude de la convection naturelle instationnaire dans des enceintes cubiques inclinées. Type de document : texte imprimé Auteurs : Khadoudja Azzouz, Auteur ; Mahfoud Djezzar, Auteur Mention d'édition : 23/06/2019 Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2019 Importance : 89 f. Format : 30 cm. Note générale : 1 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
PhysiqueTags : Physique Energétique :Photothermique convection naturelle équations de Boussinesq enceintes fermées cubiques nanofluide natural convection Boussinesq equations cubic closed enclosures nanofluid الحمل الطبيعي معادلات بوسينسك فضاء مكعب طريقة الحجوم المنتهية نانو فلويد Index. décimale : 530 Physique Résumé : In this study, we present a numerical solution of unsteady natural convection in a cubic enclosure filled with a nanofluid, inclined at an angle . The left wall at a sinusoidal temperature with time and the right wall maintained at a cold temperature Tfr and adiabatic opposite sides for a first case. In a second case of heating, we impose the opposite sides Tch and Tfr with Tch > Tfr, and both other adiabatic walls. For a third and a fourth case, periodic heating is imposed on this vertical wall. The right wall of the enclosure is maintained at a constant temperature (Tfr); however, the other walls are adiabatic.The Prandtl number is fixed at 6.2 (case of water) but the Grashof number and the volume fraction varies. Using the Boussinesq approximation. The SIMPLER algorithm was used to couple the velocity and pressure fields. We compare results from the latter with other similar results existing in the literature qualitatively or quantitatively.
Note de contenu : Annexes. Diplôme : Doctorat en sciences En ligne : ../theses/physique/AZZ7584.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11421 Contribution à l’étude de la convection naturelle instationnaire dans des enceintes cubiques inclinées. [texte imprimé] / Khadoudja Azzouz, Auteur ; Mahfoud Djezzar, Auteur . - 23/06/2019 . - جامعة الإخوة منتوري قسنطينة, 2019 . - 89 f. ; 30 cm.
1 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : Physique Energétique :Photothermique convection naturelle équations de Boussinesq enceintes fermées cubiques nanofluide natural convection Boussinesq equations cubic closed enclosures nanofluid الحمل الطبيعي معادلات بوسينسك فضاء مكعب طريقة الحجوم المنتهية نانو فلويد Index. décimale : 530 Physique Résumé : In this study, we present a numerical solution of unsteady natural convection in a cubic enclosure filled with a nanofluid, inclined at an angle . The left wall at a sinusoidal temperature with time and the right wall maintained at a cold temperature Tfr and adiabatic opposite sides for a first case. In a second case of heating, we impose the opposite sides Tch and Tfr with Tch > Tfr, and both other adiabatic walls. For a third and a fourth case, periodic heating is imposed on this vertical wall. The right wall of the enclosure is maintained at a constant temperature (Tfr); however, the other walls are adiabatic.The Prandtl number is fixed at 6.2 (case of water) but the Grashof number and the volume fraction varies. Using the Boussinesq approximation. The SIMPLER algorithm was used to couple the velocity and pressure fields. We compare results from the latter with other similar results existing in the literature qualitatively or quantitatively.
Note de contenu : Annexes. Diplôme : Doctorat en sciences En ligne : ../theses/physique/AZZ7584.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11421 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité AZZ/7584 AZZ/7584 Thèse Bibliothèque principale Thèses Disponible 
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