The aim of the present paper is to analyze the natural convection heat and mass transfer of nanofluids over a vertical plate embedded in a saturated Darcy porous medium subjected to surface heat and nanoparticle fluxe...The aim of the present paper is to analyze the natural convection heat and mass transfer of nanofluids over a vertical plate embedded in a saturated Darcy porous medium subjected to surface heat and nanoparticle fluxes. To carry out the numerical solution, two steps are performed. The governing partial differential equations are firstly simplified into a set of highly coupled nonlinear ordinary differential equations by appropriate similarity variables, and then numerically solved by the finite difference method. The obtained similarity solution depends on four non-dimensional parameters, i.e., the Brownian motion parameter （Nb）, the buoyancy ratio （Nr）, the thermophoresis parameter （Nt）, and the Lewis number （Le）. The variations of the reduced Nusselt number and the reduced Sherwood number with Nb and Nt for various values of Le and Nr are discussed in detail. Simulation results depict that the increase in Nb, Nt, or Nr decreases the reduced Nusselt number. An increase in the Lewis number increases both of the reduced Nusselt number and the Sherwood number. The results also reveal that the nanoparticle concentration boundary layer thickness is much thinner than those of the thermal and hydrodynamic boundary layers.展开更多
An integral treatment is proposed for the analysis of the forced convection flow of a nanofluid over a stretching sheet. The obtained results agree well with the numerical results. The results of the presented solutio...An integral treatment is proposed for the analysis of the forced convection flow of a nanofluid over a stretching sheet. The obtained results agree well with the numerical results. The results of the presented solution provide an analytic solution, which can be conveniently used in engineering applications. Four types of nanoparticles, i.e., alumina （Al2O3）, silicon dioxide （Si02）, silver （Ag）, and copper （Cu）, dispersed in the base fluid of water are examined. The analytical results show that an increase in the volume fraction of nanoparticles increases the thickness of the thermal boundary layer. The reduced Nusselt number is a decreasing function of the volume fraction of nanoparticles. ＇ Key words nanofluid, integral method, stretching sheet, analytical solution, thermal enhancement展开更多
基金Shahid Chamran University of Ahvaz for its support of this paper
文摘The aim of the present paper is to analyze the natural convection heat and mass transfer of nanofluids over a vertical plate embedded in a saturated Darcy porous medium subjected to surface heat and nanoparticle fluxes. To carry out the numerical solution, two steps are performed. The governing partial differential equations are firstly simplified into a set of highly coupled nonlinear ordinary differential equations by appropriate similarity variables, and then numerically solved by the finite difference method. The obtained similarity solution depends on four non-dimensional parameters, i.e., the Brownian motion parameter （Nb）, the buoyancy ratio （Nr）, the thermophoresis parameter （Nt）, and the Lewis number （Le）. The variations of the reduced Nusselt number and the reduced Sherwood number with Nb and Nt for various values of Le and Nr are discussed in detail. Simulation results depict that the increase in Nb, Nt, or Nr decreases the reduced Nusselt number. An increase in the Lewis number increases both of the reduced Nusselt number and the Sherwood number. The results also reveal that the nanoparticle concentration boundary layer thickness is much thinner than those of the thermal and hydrodynamic boundary layers.
文摘An integral treatment is proposed for the analysis of the forced convection flow of a nanofluid over a stretching sheet. The obtained results agree well with the numerical results. The results of the presented solution provide an analytic solution, which can be conveniently used in engineering applications. Four types of nanoparticles, i.e., alumina （Al2O3）, silicon dioxide （Si02）, silver （Ag）, and copper （Cu）, dispersed in the base fluid of water are examined. The analytical results show that an increase in the volume fraction of nanoparticles increases the thickness of the thermal boundary layer. The reduced Nusselt number is a decreasing function of the volume fraction of nanoparticles. ＇ Key words nanofluid, integral method, stretching sheet, analytical solution, thermal enhancement
