Flow distribution and the effects of different boundary conditions are achieved for a steady-state conjugate (Conduction & Convection) heat transfer process. A plate fin heat sink with horizontal fin orientation a...Flow distribution and the effects of different boundary conditions are achieved for a steady-state conjugate (Conduction & Convection) heat transfer process. A plate fin heat sink with horizontal fin orientation along with a computer chassis is numerically investigated and simulated using software ANSYS CFX. Fin orientation of a heat sink changes the direction of fluid flow inside the chassis. For predicting turbulence of the flow inside the domain, a two</span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">equation based</span><span style="font-size:10pt;font-family:""><span style="font-family:Verdana;font-size:12px;"> <i></span><i><span style="font-family:Verdana;font-size:12px;">k</span></i><span style="font-family:Verdana;font-size:12px;">-</span><i><span style="font-family:Verdana;font-size:12px;">ε</span></i><span style="font-family:Verdana;font-size:12px;"></i> turbulence model is chosen. The</span></span><span style="font-size:10pt;font-family:""> </span><span style="font-family:Verdana;">Reynolds number based on inflow velocity and geometry is found 4.2</span><span style="font-size:10pt;font-family:""> </span><span style="font-family:Verdana;">×</span><span style="font-size:10pt;font-family:""> </span><span style="font-family:Verdana;">10<sup>3</sup> that indicates that the flow is turbulent inside the chassis. To get proper thermal cooling, the optimum velocity ratio of inlet/outlet, dimension of inlet/outlet and different positions of outlet on the back sidewall of the chassis are predicted.</span><span style="font-size:10pt;font-family:""> </span><span style="font-family:Verdana;">Aspect</span><span style="font-family:Verdana;"> velocity ratio between the inlet airflow and the outlet airflow has an effect on the steadiness of the flow. Mass flow rate depends</span><span style="font-size:10pt;font-family:""> </span><span style="font-family:Verdana;">on the dimension of the inlet/outlet. The horizontal fin orientation with 1:1.6 inlet-outlet airflow velocity ratio gives better thermal performance when outlet is located at the top corner of the chassis, near to the inner sidewall. Flow distribution and heat transfer characteristics are also analyzed to obtain the final model.展开更多
The boundary-layer flow and heat transfer in a viscous fluid containing metallic nanoparticles over a nonlinear stretching sheet are analyzed. The stretching velocity is assumed to vary as a power function of the dist...The boundary-layer flow and heat transfer in a viscous fluid containing metallic nanoparticles over a nonlinear stretching sheet are analyzed. The stretching velocity is assumed to vary as a power function of the distance from the origin. The governing partial differential equation and auxiliary conditions are reduced to coupled nonlinear ordinary differential equations with the appropriate corresponding auxiliary conditions. The resulting nonlinear ordinary differential equations （ODEs） are solved numerically. The effects of various relevant parameters, namely, the Eckert number Ec, the solid volume fraction of the nanoparticles ~, and the nonlinear stretching parameter n are discussed. The comparison with published results is also presented. Different types of nanoparticles are studied. It is shown that the behavior of the fluid flow changes with the change of the nanoparticles type.展开更多
文摘Flow distribution and the effects of different boundary conditions are achieved for a steady-state conjugate (Conduction & Convection) heat transfer process. A plate fin heat sink with horizontal fin orientation along with a computer chassis is numerically investigated and simulated using software ANSYS CFX. Fin orientation of a heat sink changes the direction of fluid flow inside the chassis. For predicting turbulence of the flow inside the domain, a two</span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">equation based</span><span style="font-size:10pt;font-family:""><span style="font-family:Verdana;font-size:12px;"> <i></span><i><span style="font-family:Verdana;font-size:12px;">k</span></i><span style="font-family:Verdana;font-size:12px;">-</span><i><span style="font-family:Verdana;font-size:12px;">ε</span></i><span style="font-family:Verdana;font-size:12px;"></i> turbulence model is chosen. The</span></span><span style="font-size:10pt;font-family:""> </span><span style="font-family:Verdana;">Reynolds number based on inflow velocity and geometry is found 4.2</span><span style="font-size:10pt;font-family:""> </span><span style="font-family:Verdana;">×</span><span style="font-size:10pt;font-family:""> </span><span style="font-family:Verdana;">10<sup>3</sup> that indicates that the flow is turbulent inside the chassis. To get proper thermal cooling, the optimum velocity ratio of inlet/outlet, dimension of inlet/outlet and different positions of outlet on the back sidewall of the chassis are predicted.</span><span style="font-size:10pt;font-family:""> </span><span style="font-family:Verdana;">Aspect</span><span style="font-family:Verdana;"> velocity ratio between the inlet airflow and the outlet airflow has an effect on the steadiness of the flow. Mass flow rate depends</span><span style="font-size:10pt;font-family:""> </span><span style="font-family:Verdana;">on the dimension of the inlet/outlet. The horizontal fin orientation with 1:1.6 inlet-outlet airflow velocity ratio gives better thermal performance when outlet is located at the top corner of the chassis, near to the inner sidewall. Flow distribution and heat transfer characteristics are also analyzed to obtain the final model.
文摘The boundary-layer flow and heat transfer in a viscous fluid containing metallic nanoparticles over a nonlinear stretching sheet are analyzed. The stretching velocity is assumed to vary as a power function of the distance from the origin. The governing partial differential equation and auxiliary conditions are reduced to coupled nonlinear ordinary differential equations with the appropriate corresponding auxiliary conditions. The resulting nonlinear ordinary differential equations （ODEs） are solved numerically. The effects of various relevant parameters, namely, the Eckert number Ec, the solid volume fraction of the nanoparticles ~, and the nonlinear stretching parameter n are discussed. The comparison with published results is also presented. Different types of nanoparticles are studied. It is shown that the behavior of the fluid flow changes with the change of the nanoparticles type.
