网格划分对汽车外流场数值计算影响的研究

基于Mira国际标模，采用三种网格方案，每种方案采用两种网格密度，研究其对汽车外流场仿真计算的影响，并与风洞试验数据进行对比。结果表明：三棱柱、四面体及六面体混合方案精度得到有效改善；完全六面体方案由于很难控制的低质量网格导致计算发散，挖掘六面体网格优势是今后的趋势；网格密度对仿真计算的影响主要是基于壁面层网格尺寸，在壁面函数有效范围内，适当减小其尺寸，可以使计算精度得到有效改善。

Effect of Meshing on Numerical Simulation of External Flow Field around Vehicle

Numerical simulation was carried out to discuss the effect of variable meshing approaches and densities on vehicle external flow field based on international standard model Mira and used three mesh strategies concluded two densities.Comparing results with Wind Tunnel experiment data.The results show that Tetra, Prism and Hexa mix mesh strategy gets a realizable result.The accuracy is effectively improved.Full Hexa strategy results in solution diffusion because of the hardly controlled low quality grid.Mining advantages of the hexahedral grid is the future trend. The effect of mesh density on solution results mainly base on near-wall grid size.It should be in the effective zone of the wall function. It would refine the solution accuracy effectively by reducing its size properly.