Documents disponibles écrits par cet auteur

Effect of turbulent prandtl number on convective heat transfer to turbulent flow of a supercritical fluid in a vertical round tube / Mahdi Mohseni in Journal of heat transfer, Vol. 133 N° 7 (Juillet 2011) 

Public ISBD [article]  in Journal of heat transfer > Vol. 133 N° 7 (Juillet 2011) . - pp. [071701/1-10] Titre : Effect of turbulent prandtl number on convective heat transfer to turbulent flow of a supercritical fluid in a vertical round tube Type de document : texte imprimé Auteurs : Mahdi Mohseni, Auteur ; Majid Bazargan, Auteur Année de publication : 2011 Article en page(s) : pp. [071701/1-10] Note générale : Physique Langues : Anglais (eng) Mots-clés : Turbulent  prandtl  number  Supercritical  fluid  flow  Convective  transfer  Numerical  simulation Index. décimale : 536 Chaleur. Thermodynamique Résumé : A two-dimensional numerical model is developed to study the effect of the turbulent Prandtl number Prt on momentum and energy transport in a highly variable property flow of supercritical fluids in a vertical round tube. Both regimes of enhanced and deteriorated heat transfer have been investigated. The equations of the Prt leading to the best agreement with the experiments in either regime of heat transfer were specified. The results of this study show that the increase in the Prt causes the heat transfer coefficients to decrease. When the buoyancy force increases, a better agreement with the experimental data is reached if values lower than 0.9 are used for the Prt. A decrease in the Prt values results in an increase in turbulent activities. From the effect that the Prt has on heat transfer coefficients, it may be deduced that the buoyancy effects in the upward flow of a supercritical fluid lead to the decrease in the Prt value and hence to the increase in the heat transfer coefficients. Furthermore, the value of the Prt in the laminar viscous sublayer as expected does not have a significant effect on heat transfer rate. The effect of the turbulence model on the extent to which the Prt influences the rate of heat transfer is also examined. The results obtained are shown to be valid regardless of the turbulence model used. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JHTRAO00013300 [...] [article] Effect of turbulent prandtl number on convective heat transfer to turbulent flow of a supercritical fluid in a vertical round tube [texte imprimé] / Mahdi Mohseni, Auteur ; Majid Bazargan, Auteur . - 2011 . - pp. [071701/1-10]. Physique Langues : Anglais (eng) in Journal of heat transfer > Vol. 133 N° 7 (Juillet 2011) . - pp. [071701/1-10] Mots-clés : Turbulent  prandtl  number  Supercritical  fluid  flow  Convective  transfer  Numerical  simulation Index. décimale : 536 Chaleur. Thermodynamique Résumé : A two-dimensional numerical model is developed to study the effect of the turbulent Prandtl number Prt on momentum and energy transport in a highly variable property flow of supercritical fluids in a vertical round tube. Both regimes of enhanced and deteriorated heat transfer have been investigated. The equations of the Prt leading to the best agreement with the experiments in either regime of heat transfer were specified. The results of this study show that the increase in the Prt causes the heat transfer coefficients to decrease. When the buoyancy force increases, a better agreement with the experimental data is reached if values lower than 0.9 are used for the Prt. A decrease in the Prt values results in an increase in turbulent activities. From the effect that the Prt has on heat transfer coefficients, it may be deduced that the buoyancy effects in the upward flow of a supercritical fluid lead to the decrease in the Prt value and hence to the increase in the heat transfer coefficients. Furthermore, the value of the Prt in the laminar viscous sublayer as expected does not have a significant effect on heat transfer rate. The effect of the turbulence model on the extent to which the Prt influences the rate of heat transfer is also examined. The results obtained are shown to be valid regardless of the turbulence model used. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JHTRAO00013300 [...]

Modeling of free convection heat transfer to a supercritical fluid in a square enclosure by the lattice Boltzmann method / Mostafa Varmazyar in Journal of heat transfer, Vol. 133 N° 2 (Fevrier 2011) 

Public ISBD [article]  in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [022501/1-5] Titre : Modeling of free convection heat transfer to a supercritical fluid in a square enclosure by the lattice Boltzmann method Type de document : texte imprimé Auteurs : Mostafa Varmazyar, Auteur ; Majid Bazargan, Auteur Année de publication : 2011 Article en page(s) : pp. [022501/1-5] Note générale : Physique Langues : Anglais (eng) Mots-clés : Lattice  Boltzmann  method  Energy  equation  Supercritical  fluid  flow  Cavity  enclosure  Free  convection Index. décimale : 536 Chaleur. Thermodynamique Résumé : During the last decade, a number of numerical computations based on the finite volume approach have been reported, studying various aspects of heat transfer near the critical point. In this paper, a lattice Boltzmann method (LBM) has been developed to simulate laminar free convection heat transfer to a supercritical fluid in a square enclosure. The LBM is an ideal mesoscopic approach to solve nonlinear macroscopic conservation equations due to its simplicity and capability of parallelization. The lattice Boltzmann equation (LBE) represents the minimal form of the Boltzmann kinetic equation. The LBE is a very elegant and simple equation, for a discrete density distribution function, and is the basis of the LBM. For the mass and momentum equations, a LBM is used while the heat equation is solved numerically by a finite volume scheme. In this study, interparticle forces are taken into account for nonideal gases in order to simulate the velocity profile more accurately. The laminar free convection cavity flow has been extensively used as a benchmark test to evaluate the accuracy of the numerical code. It is found that the numerical results of this study are in good agreement with the experimental and numerical results reported in the literature. The results of the LBM-FVM (finite volume method) combination are found to be in excellent agreement with the FVM-FVM combination for the Navier–Stokes and heat transfer equations. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Modeling of free convection heat transfer to a supercritical fluid in a square enclosure by the lattice Boltzmann method [texte imprimé] / Mostafa Varmazyar, Auteur ; Majid Bazargan, Auteur . - 2011 . - pp. [022501/1-5]. Physique Langues : Anglais (eng) in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [022501/1-5] Mots-clés : Lattice  Boltzmann  method  Energy  equation  Supercritical  fluid  flow  Cavity  enclosure  Free  convection Index. décimale : 536 Chaleur. Thermodynamique Résumé : During the last decade, a number of numerical computations based on the finite volume approach have been reported, studying various aspects of heat transfer near the critical point. In this paper, a lattice Boltzmann method (LBM) has been developed to simulate laminar free convection heat transfer to a supercritical fluid in a square enclosure. The LBM is an ideal mesoscopic approach to solve nonlinear macroscopic conservation equations due to its simplicity and capability of parallelization. The lattice Boltzmann equation (LBE) represents the minimal form of the Boltzmann kinetic equation. The LBE is a very elegant and simple equation, for a discrete density distribution function, and is the basis of the LBM. For the mass and momentum equations, a LBM is used while the heat equation is solved numerically by a finite volume scheme. In this study, interparticle forces are taken into account for nonideal gases in order to simulate the velocity profile more accurately. The laminar free convection cavity flow has been extensively used as a benchmark test to evaluate the accuracy of the numerical code. It is found that the numerical results of this study are in good agreement with the experimental and numerical results reported in the literature. The results of the LBM-FVM (finite volume method) combination are found to be in excellent agreement with the FVM-FVM combination for the Navier–Stokes and heat transfer equations. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]