理学院:数学与数据科学应用研究所系列报告:The positivity-preserving numerical method for compressible multi-media flow

发布者:综合科发布时间:2020-10-10浏览次数:199

                            报告题目:    The positivity-preserving numerical method

for compressible multi-media flow

报告人:         王春武  教授(博导)

报告人单位: 南京航空航天大学理学院

报告日期:     20201012日星期一

报告时间:     10:00-11:30

报告地点:     江宁校区励学楼B 219

邀请人    朱永忠

欢迎广大师生参加。    
        摘要In the numerical simulations of the multi-medium ow such as blast waves or high-velocity jets, the negative density or pressure (or internal energy) may occur in the flow and low pressure domain due to the numerical errors of the high order schemes. The loss of positivity of the physically positive variables may lead to nonlinear instability or blow-ups of the algorithm. In this paper, we present a positivity-preserving algorithm for the compressible multi-media flow. The real Ghost Fluid method (RGFM) is coupled to the positivity-preserving Runge-Kutta discontinuous Galerkin (RKDG) schemes for single medium flow to treat the interface. The two-shock approximate Riemann problems are used to produce the fluid states at the interface. To solve the Riemann problems at the interface in RGFM, an iteration method is constructed and proved to be able to give the positive solver of density and pressure if the initial data is positive. Several numerical examples are given to test robustness and efficiency of the algorithm. Numerical results show that the obtained method can maintain the positivity of density and pressure and capture the discontinuities accurately.

        报告人简介: 王春武,教授,博士生导师。2000年毕业于南京航空航天大学航空学院,获流体力学博士学位。现任南京航空航天大学理学院院长,中国工业与应用数学学会理事,江苏省数学会副理事长。主要从事多介质流体力学高精度数值模拟方法研究,主持国家自然科学基金、国防基础物理专项、国防基础科研核科学挑战专题和国防预研项目,在《SIAM J. Sci. Comput》、《J. Comput. Phys.》等国内外重要期刊发表论文30余篇。