一种基于自适应碰撞距离的DSMC虚拟子网格方法

A virtual sub-cells technique with transient adaptive collision distance for the DSMC method

为提高DSMC方法的计算效率及其对较高密度稀薄流问题的模拟能力,针对其碰撞对抽样环节,发展了基于自适应碰撞距离的虚拟子网格方法,并通过平板、钝锥等典型算例验证了该方法的正确性。结果表明:虚拟子网格技术放宽了DSMC方法对网格尺度的要求,可以在较大的网格尺度下得到满足计算精度要求的结果。

A new sampling solution method of virtual sub-cells technique based on transient adaptive col-lision distance for collision pair selection was introduced to improve simulation efficiency in DSMC.The new method was validated by comparing standard method’s results with new method’s results of both flat plate and blunt cone aerodynamics under different grid cells.The results show that the cell size constraint of the DSMC method could be relaxed to a limited extent when the cells are supplemented by the virtual sub-cells, and aerodynamics of flat plate and blunt cone under coarse grid size with this virtual method is consistent with fine grid results.