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Auteur Lakhdar Bahi |
Documents disponibles écrits par cet auteur (3)
Affiner la recherche Interroger des sources externesContrôle de la couche limite laminaire d’un écoulement stationnaire, visqueux, compressible et subsonique autour d’un profil bidimensionnel / Azzeddine Nahoui
Titre : Contrôle de la couche limite laminaire d’un écoulement stationnaire, visqueux, compressible et subsonique autour d’un profil bidimensionnel Type de document : texte imprimé Auteurs : Azzeddine Nahoui, Auteur ; Lakhdar Bahi, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2018 Importance : 116 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
PhysiqueTags : Couche limite laminaire compressible nombre de Mach nombre de Reynolds contrôle point de séparation aspiration soufflage refroidissement pariétal Laminar boundary layer Mach number Reynolds number control separation point suction blowing wall cooling طبقة حدية رقائقية انضغاطي عدد ماخ عدد رينولدز مراقبة نقطة الانفصال الامتصاص النفخ والتبريد السطحي Index. décimale : 530 Physique Résumé : A numerical study of a laminar boundary layer of a stationary, viscous, compressible and subsonic flow around a two-dimensional NACA profile was conducted without and with control.
The flow domain has been divided into two zones, one near-wall, the boundary layer, which is responsible for friction phenomena, and the other, an external zone where flow is considered potential.
The potential flow is studied by the panel method for the determination of the external velocity distribution necessary for the treatment of the boundary layer.
The boundary layer was studied using the PRANDTL model and the KELLER method by reducing the order of the first-order differential equations, the writing of the algebraic equations, and the linearization by the Newton method via an iterative calculation process and finally the resolution by the method of elimination by blocks.
The distributions of the pressure and lift coefficients were determined and examined for different Mach numbers and different angles of attack with varying relative thickness.
Thermal control by wall heating or wall cooling was studied and the results demonstrated only the effectiveness of the wall cooling control on the recoil of the separation point around 10% of the chord of the profile.
The dynamic control by suction or blowing has demonstrated its effectiveness on the decline of the separation point; the decline has reached 10% of the chord of the profile.
The superimposition of the thermal and dynamic control procedures demonstrated once again more efficiency on the retreat of the boundary layer separation point with a gain of 15% of the chord of the profile.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/NAH7251.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10843 Contrôle de la couche limite laminaire d’un écoulement stationnaire, visqueux, compressible et subsonique autour d’un profil bidimensionnel [texte imprimé] / Azzeddine Nahoui, Auteur ; Lakhdar Bahi, Directeur de thèse . - جامعة الإخوة منتوري قسنطينة, 2018 . - 116 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : Couche limite laminaire compressible nombre de Mach nombre de Reynolds contrôle point de séparation aspiration soufflage refroidissement pariétal Laminar boundary layer Mach number Reynolds number control separation point suction blowing wall cooling طبقة حدية رقائقية انضغاطي عدد ماخ عدد رينولدز مراقبة نقطة الانفصال الامتصاص النفخ والتبريد السطحي Index. décimale : 530 Physique Résumé : A numerical study of a laminar boundary layer of a stationary, viscous, compressible and subsonic flow around a two-dimensional NACA profile was conducted without and with control.
The flow domain has been divided into two zones, one near-wall, the boundary layer, which is responsible for friction phenomena, and the other, an external zone where flow is considered potential.
The potential flow is studied by the panel method for the determination of the external velocity distribution necessary for the treatment of the boundary layer.
The boundary layer was studied using the PRANDTL model and the KELLER method by reducing the order of the first-order differential equations, the writing of the algebraic equations, and the linearization by the Newton method via an iterative calculation process and finally the resolution by the method of elimination by blocks.
The distributions of the pressure and lift coefficients were determined and examined for different Mach numbers and different angles of attack with varying relative thickness.
Thermal control by wall heating or wall cooling was studied and the results demonstrated only the effectiveness of the wall cooling control on the recoil of the separation point around 10% of the chord of the profile.
The dynamic control by suction or blowing has demonstrated its effectiveness on the decline of the separation point; the decline has reached 10% of the chord of the profile.
The superimposition of the thermal and dynamic control procedures demonstrated once again more efficiency on the retreat of the boundary layer separation point with a gain of 15% of the chord of the profile.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/NAH7251.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=10843 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité NAH/7251 NAH/7251 Thèse Bibliothèque principale Thèses Disponible
Titre : Etude de vibration des pales d' aerogenerateur. Auteurs : Zine-Labidine Mahri ; Univ. de Constantine, Éditeur scientifique ; Lakhdar Bahi, Directeur de thèse Année de publication : 1991 Importance : 147 f. Note générale : 02 Disponibles au magazin de la bibliotheque centrale Langues : Français (fre) Catégories : Français - Anglais
Génie ClimatiqueTags : Vibration des pales Aerogenerateur Index. décimale : 626 Génie Climatique Permalink : index.php?lvl=notice_display&id=4 Etude de vibration des pales d' aerogenerateur. [] / Zine-Labidine Mahri ; Univ. de Constantine, Éditeur scientifique ; Lakhdar Bahi, Directeur de thèse . - 1991 . - 147 f.
02 Disponibles au magazin de la bibliotheque centrale
Langues : Français (fre)
Catégories : Français - Anglais
Génie ClimatiqueTags : Vibration des pales Aerogenerateur Index. décimale : 626 Génie Climatique Permalink : index.php?lvl=notice_display&id=4 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité MAH/2241 MAH/2241 Thèse Bibliothèque principale Thèses Disponible
Titre : Simulation numérique du contrôle de l’écoulement décollé autour de profils. Type de document : texte imprimé Auteurs : Mohamed chérif Saadi, Auteur ; Lakhdar Bahi, Directeur de thèse Mention d'édition : 20/09/2020 Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2020 Importance : 99 f. Note générale : 1 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
PhysiqueTags : Physique Energétique: Photo-thermique Contrôle synthétique jet écoulement visqueux turbulent incompressible décollement profil NACA symétrique portance trainée Control synthetic flow viscous separation profile symmetrical lift drag التحكم نفث اصطناعي جريان لزج مضطرب غير قابل للانضغاط انفصال مقاطع متناظرة حمل جر Index. décimale : 530 Physique Résumé : The efficiency of a synthetic jet control on the separation of a turbulent, incompressible and viscous flow around a NACA symmetrical profile, is studied numerically using two transport equations turbulent model k-ε RNG. The numerical resolution of the equations governing the physical problem, is done using the commercial code ""Fluent"" and a mesh generation software ""gambit"". The discretization of the non-linear, partial differential equations, is obtained using the finite volumes method. The lift and drag coefficient distributions and the velocity field and thus the streamlines flow field, are calculated and analyzed with and without control to find out the control efficiency. A parametric study of the jet control defined by the jet angle and its location, the jet width as well as its frequency, is carried out. By varying the angle and the location of the jet, the results show that a jet angle equal to 45° situated at 15% from the leading edge, reduce more the size of the separated region. Also, a 2% jet width for different jet angles, leads to a better control efficiency with a more reduction of the separated zone and a better increase in lift. Finally, by varying the jet frequency F+ and the jet velocity Vr, the separated zone disappears completely for a frequency equal to 2.5 and any Vr bigger than 2. The study done over different symmetrical NACA profiles, show that the control concept is as much efficient as the profile is thin producing a better increase in performances. Diplôme : Doctorat en sciences En ligne : ../theses/physique/SAA7650.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11484 Simulation numérique du contrôle de l’écoulement décollé autour de profils. [texte imprimé] / Mohamed chérif Saadi, Auteur ; Lakhdar Bahi, Directeur de thèse . - 20/09/2020 . - جامعة الإخوة منتوري قسنطينة, 2020 . - 99 f.
1 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : Physique Energétique: Photo-thermique Contrôle synthétique jet écoulement visqueux turbulent incompressible décollement profil NACA symétrique portance trainée Control synthetic flow viscous separation profile symmetrical lift drag التحكم نفث اصطناعي جريان لزج مضطرب غير قابل للانضغاط انفصال مقاطع متناظرة حمل جر Index. décimale : 530 Physique Résumé : The efficiency of a synthetic jet control on the separation of a turbulent, incompressible and viscous flow around a NACA symmetrical profile, is studied numerically using two transport equations turbulent model k-ε RNG. The numerical resolution of the equations governing the physical problem, is done using the commercial code ""Fluent"" and a mesh generation software ""gambit"". The discretization of the non-linear, partial differential equations, is obtained using the finite volumes method. The lift and drag coefficient distributions and the velocity field and thus the streamlines flow field, are calculated and analyzed with and without control to find out the control efficiency. A parametric study of the jet control defined by the jet angle and its location, the jet width as well as its frequency, is carried out. By varying the angle and the location of the jet, the results show that a jet angle equal to 45° situated at 15% from the leading edge, reduce more the size of the separated region. Also, a 2% jet width for different jet angles, leads to a better control efficiency with a more reduction of the separated zone and a better increase in lift. Finally, by varying the jet frequency F+ and the jet velocity Vr, the separated zone disappears completely for a frequency equal to 2.5 and any Vr bigger than 2. The study done over different symmetrical NACA profiles, show that the control concept is as much efficient as the profile is thin producing a better increase in performances. Diplôme : Doctorat en sciences En ligne : ../theses/physique/SAA7650.pdf Format de la ressource électronique : Permalink : index.php?lvl=notice_display&id=11484 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité SAA/7650 SAA/7650 Thèse Bibliothèque principale Thèses Disponible
