沈智军 研究员 (北京应用物理与计算数学研究所）

袁礼 研究员

A staggered Lagrangian magnetohydrodynamics method based onsubcell Riemann solver

3月19日（周四）15:00-16:00，南楼213

This work uses a general formalism to derive staggered Lagrangian method for 2D compressible magnetohydrodynamics (MHD) flows. A subcell method is introduced to discretize the MHD system and some Riemann problems over subcells are solved at the cell center and grid node respectively. In these solvers, only the fast-waves in all jumping relations are considered and thus the solution structure is simple. The discrete conservations of mass, momentum and energy are preserved naturally. In order to meet the thermodynamic Gibbs relation in isentropic flows, an adaptive Riemann solver is implemented at the cell center, in which a criterion is proposed to reduce overheating errors in the rarefying problems and maintains the excellent shock-capturing ability simultaneously. It is worth to be noticed that the divergence-free condition is naturally satisfied in the Lagrangian method. Various numerical tests are presented to demonstrate the accuracy and robustness of the algorithm.

报告人简介：北京应用物理与计算数学研究所研究员，博士生导师，北京大学工学院兼职研究员，北京师范大学文理学院兼职教授，中国科协智慧科技人才评审专家成员。本科毕业于浙江大学数学系，博士毕业于中国工程物理研究院研究生部。长期从事中子输运方程、辐射扩散方程和流体力学方程组的数值方法研究。曾两次荣获国防科工委科技进步二等奖。在包括 J. comput. Phy., SIAM. Sci. Comput. 等重要期刊上发表 SCI 论文七十余篇。