两种修正达西模型对平板通道内流动换热的影响

采用数值模拟的方法,对层流状态下恒热流壁面平板通道完全填充多孔介质的流动换热进行了相关研究.通过局部热平衡模型描述多孔介质内的换热,分别用Brinkman-Darcy流动模型和Brinkman-Forchheimer-Darcy流动模型描述多孔介质内的流动,并对比了两种流动模型下的流动换热性能.结果表明:Re数较小时,两种流动模型下的换热差异很小(壁面平均Nu数相差1%);随着Re数的增大,两种流动模型下的速度场和温度场差异增大,因而为了更准确的描述添加多孔介质后通道内的流动换热变化,在Re数较大时,需采用BDF流动模型.

Effects of Two Modified Darcy Models on Flow and Heat Transfer in the Parallel Plate Channel

The flow and heat transfer of the Parallel Plate Channel with constant heat-flux walls filled with porous blocks was studied by the numerical simulation method. By using the local thermal equilibrium model, the heat transfer in porous blocks was described, and the flow and heat transfer performances of the channel by using the BD model and the BDF model were compared. The result shows that when the Re number is smaller, the differences of flow and heat transfer between the two models is tiny, but with the in crease of Re number, the differences of velocity field and temperature field between the two models be- comes larger. Therefore, when the Re number is large, the BDF flow model has to be adopted to more accu- rately describe the changes of flow and heat transfer in the channel filled with porous blocks.