球床通道内CFD网格适用性分析

Analysis of Grid Applicability in the CFD of Packed Bed

为了研究球床通道内网格效应对CFD计算精度的影响,本文采用两类网格划分形式,对体心堆积结构球床通道内层流和湍流下的阻力和传热特性进行了数值计算。通过对比发现:在层流时,流道内的整体网格密度是决定阻力和传热特性计算结果精度的主要因素,在相同条件下,阻力对网格密度的依赖程度大于传热。而湍流时,决定阻力和传热特性计算结果精度的主要因素是近壁面网格数量,通过构建贴体附面层网格,能够在保证计算精度的条件下,有效地控制整体网格数量。

To develop meshes for computational fluid dynamics simulations of flow and heat transfer in packed bed.Adapting two types of meshing strategies,the flow resistance and heat transfer characteristics in structure packed bed of body-centered packing under laminar and turbulent flows were calculated.The results show that,in the laminar flow,the global mesh density is the main factor,which to determine the accuracy of calculated results of flow resistance and heat transfer,and the dependence of flow resistance on the mesh density is greater than heat transfer.Under Turbulence flow condition,the near-wall mesh count is the main factor.By constructing the boundary layer of body-fitted grid is not only to improve the accuracy of results but also to control the overall number of grid effectively.