The work presented herein investigates the velocity, heat transfer, Nusselt number and skin friction profiles involved in boundary layer flow past a moving vertical porous plate. Similarity transformations are employe...The work presented herein investigates the velocity, heat transfer, Nusselt number and skin friction profiles involved in boundary layer flow past a moving vertical porous plate. Similarity transformations are employed to convert the governing nonlinear unsteady momentum and energy equations from their partial differential equation forms to boundary value ordinary differential equations. The resulting equations are then solved numerically by the Runge-Kutta fourth order method with the help of a shooting technique. Several features of the flow and heat transfer characteristics for different values of problem parameters are analyzed and discussed. These include the effects of the radiation parameter (R), suction and injection parameter (c), Grashof (Gr) and Prandtl (Pr) numbers on the flow and heat profiles. Numerical results show the impact of blowing and sucking as well as radation on boundary layer flows of this type. Both the skin frictions as well as the heat transfer rate are also significantly related to the radiation parameter. For all these cases;the numerical results are found to be in agreement with the physics of the problem.展开更多
In this paper,we study hydrodynamics and thermal behaviors of micro-heat exchanger of different cross sections,with hydraulic diameters(D_h)of 0.4-0.8 mm and Reynolds numbers(Re)of 300-900.Validity of the model is pro...In this paper,we study hydrodynamics and thermal behaviors of micro-heat exchanger of different cross sections,with hydraulic diameters(D_h)of 0.4-0.8 mm and Reynolds numbers(Re)of 300-900.Validity of the model is proved by comparing simulation results based on classical Navier-Stokes equations with experimental data and Tuckerman correlation.Effects of dynamic viscosity,hydraulic diameter,Reynolds number and cross section of the micro-channels are investigated.The results indicate that the variable viscosity effect should be taken into account,and rod bundle micro-channels have the highest heat transfer coefficient of the three types of micro-channels.展开更多
文摘The work presented herein investigates the velocity, heat transfer, Nusselt number and skin friction profiles involved in boundary layer flow past a moving vertical porous plate. Similarity transformations are employed to convert the governing nonlinear unsteady momentum and energy equations from their partial differential equation forms to boundary value ordinary differential equations. The resulting equations are then solved numerically by the Runge-Kutta fourth order method with the help of a shooting technique. Several features of the flow and heat transfer characteristics for different values of problem parameters are analyzed and discussed. These include the effects of the radiation parameter (R), suction and injection parameter (c), Grashof (Gr) and Prandtl (Pr) numbers on the flow and heat profiles. Numerical results show the impact of blowing and sucking as well as radation on boundary layer flows of this type. Both the skin frictions as well as the heat transfer rate are also significantly related to the radiation parameter. For all these cases;the numerical results are found to be in agreement with the physics of the problem.
基金Supported by National Natural Science Foundation of China(No.51106067)China Postdoctoral Science Foundation(No.2012M511212)Foundation of Priority Academic Program Development of JiangsuHigher Education Institutions
文摘In this paper,we study hydrodynamics and thermal behaviors of micro-heat exchanger of different cross sections,with hydraulic diameters(D_h)of 0.4-0.8 mm and Reynolds numbers(Re)of 300-900.Validity of the model is proved by comparing simulation results based on classical Navier-Stokes equations with experimental data and Tuckerman correlation.Effects of dynamic viscosity,hydraulic diameter,Reynolds number and cross section of the micro-channels are investigated.The results indicate that the variable viscosity effect should be taken into account,and rod bundle micro-channels have the highest heat transfer coefficient of the three types of micro-channels.
