在有热源/热汇的竖直通道中作混合对流时的第3类边界条件

Mixed Convection Flow in a Vertical Channel With Boundary Conditions of the Third Kind in the Presence of Heat Source/Sink

在竖向平行板通道中,研究粘性耗散和热源/热汇对充分发展的混合层状对流的影响.平板与外部流体进行了热交换,考虑了两种边界条件:与外部流体的参考温度相同的和不相同的.首先,数值地求解Brinkman数或Grashof数可以忽略的简单情况,然后,运用摄动级数法分析有热源/热汇存在时,浮力和粘性耗散对流动的组合影响,并证明摄动参数不大时是有效的.为了放宽摄动参数的使用条件,运用4阶Runge-Kutta打靶法,求解速度和温度场,对平板处的速度、温度、表面摩擦和Nusselt数进行数值讨论并绘出图形.

The effects of viscous dissipation and heat source/sink on fltUy-developed mixed convection for the laminar flow in a parallel-plate vertical channel were investigated. The plate exchanged heat with an external fluid. Both conditions of equal and of different reference tem- peratures of the external fluid were considered. First, the simple cases of negligible Brinkman number or negligible Grashof number were solved analytically. Then, the combined effects of buoyancy forces and viscous dissipation in the presence of heat source/sink were analyzed by a perturbation series method valid for small values of perturbation parameter. To relax the condi- tions on perturbation parameter, the velocity and temperature fields were solved using Runge- Kutta fourth-order method with shooting technique. The velocity, temperature, skin friction and Nusselt numbers at the plates were discussed numerically and presented through graphs.