基于Riemann问题的可压缩多介质流体数值模拟及在二维爆炸冲击波传播问题中的应用

Numerical Simulation of Multi-material Compressible Flows Based on Riemann Problem and Its Application in Two-dimensional Blast Wave Propagation

为有效提高可压缩多介质流体数值模拟的精度和稳定性,需要准确描述界面的位置以及界面两侧介质间的相互作用.针对J WL、多项式等具有高度非线性状态方程的多种流体间的相互作用问题,提出了一种通用、高效、误差可控的Riemann问题求解方法,能有效提高物质界面上各物理量的计算精度.结合Euler坐标系下的可压缩多介质流体数值方法,建立了一套能够模拟具有高密度比、高压力比以及复杂状态方程的二维多介质流体计算体系;结合网格自适应技术,对TNT空中爆炸自由场、TNT爆炸近区冲击波反射和水下爆炸等问题进行了数值模拟,并与实测结果进行了对比.结果表明,数值计算的爆炸冲击波参数与相关实测结果一致,表明该方法可用于复杂环境下爆炸冲击波传播规律的研究.

In order to effectively improve the accuracy and stability of the numerical simulation of compressible multi-material flows,it is necessary to accurately describe the location of the interface and the interaction between the two sides of the interface.Herein,a general,efficient and error controllable Riemann problem solving method was proposed to solve the interaction problems of various fluids with highly nonlinear state equations such as JWL and polynomials,which can effectively improve the calculation accuracy of physical quantities on the material interface.Combined with the compressible multi-material flow scheme,a two-dimensional numerical system to simulate the multi-physical problem with high density and pressure ratio was established.With the help of mesh adaptive technique,the propagation of TNT explosion in free air,reflection on near rigid ground,and underwater explosion were simulated and compared with test results.The results show that the calculated blast wave parameters agree well with the experimental data,which ensure that this numerical methods can be used to simulate the blast wave propagation in complex environments.