球坐标系下多介质混合物模型的数值模拟

Numerical simulation about the multi-component mixture model under spherical coordinate system

利用多介质混合模型在求解球坐标系下的Riemann问题时,需要考虑界面处压力平衡性弱、奇点处理、状态方程复杂等多个难点。本文将原始基于体积分数的Mie-Grüneisen多介质混合模型扩展到球坐标系下,并对多个细节进行了修正和改进,包括:在界面处对热力学参数进行修正、采用质量分数导出新输送方程、利用质量分数加权计算偏导数、采用相邻网格点的物理量定义奇点等。经过改进后的计算模型,可以得到无振荡的数值解,而且可以准确捕捉到冲击波和界面的位置。另外,使用改进后的质量分数模型比原始的体积分数模型得到的计算结果更准确。

The aim of the paper is to extend the Mie-Grüneisen mixture model to spherical coordinate. As the multi-component mixture model is applied to the Riemann problem under spherical coordinate, many problems need to be taken into account: weak equilibrium, singular point treatment, complex equations of states and so on. In the article, the research work starts from the Mie-Grüneisen mixture model, then extend to the revision and modification about many details, include: revision of the thermo dynamical parameters at interface, deduction of new transport equation by mass fraction, weighting evaluation of partial derivatives by mass fraction, definition of physical parameters by the adjacent grid for singular point and other so on. The seriously modified numerical model, can not only obtain non-oscillation solutions, but also catch the positions of shock wave and interface clearly. In addition, the modified mass fraction model, can get more accurate results than the original model with mass fraction.