二维热化学非平衡流动的非结构网格DSMC方法及其应用

研究了二维热化学非平衡流动非结构网格DSMC方法实现的过程。提出了一种新型的高效搜索算法,该算法不仅可以跟踪模拟分子在网格之间的迁移,而且在搜索过程中可以准确判别分子与物面是否相互作用,避免了原有算法中分子表面反射非确定论判据。为加快流场的时间发展历程,设计了适合DSMC方法的动态局部时间步长技术,使其可以应用到定常和非定常流场的计算。利用Fortran90的动态分配内存技术编制了计算程序。最后对过渡流域高超声速圆柱绕流进行了数值试验,计算结果初步验证了该算法的可行性。

The implementation of unstructured DSMC method for 2D thermodynamic and chemical reaction non-equilibrium flow and its application

Unstructured DSMC method is studied to calculate 2D thermodynamic and chemical reaction non-equilibrium flow;a new automatic searching algorithm is presented,by which the deterministic criterion is used for a molecule to reflect on a certain surface element instead of a probabilistic one.In order to accelerate the development of flow field and save running time,an adaptive local time stepping is designed.Dynamic allocation feature of Fortran90 is fully exploited which makes the code more flexible.Finally,numerical experiments are made for hypersonic rarefied gas flow past a circular cylinder.In some extent,the numerical results confirm the feasibility of method mentioned above.