激波和单列水柱、气水固多界面相互作用的数值模拟

Numerical Simulation of Planar Moving Shock Interacting with a Single Row of Water Columns and Multi-material Interfaces

研究可压缩多介质流场的激波和多介质界面相互作用问题.在Descartes固定网格采用level-set方法追踪界面,气/气界面边界条件处理采用OGFM方法,采用修正的r GFM方法提高气/水和气/固界面处构造Riemann问题精度,将Riemann近似解得到的界面参数外推到两侧真实和虚拟流体,采用五阶WENO方法求解流场Euler方程和界面level-set方程,给出不同时刻流场数值纹影图像.结果表明：在可压缩流场嵌入固体和水、气体等目标,本文方法可较精确地分辨平面运动激波和单列水柱及包含气/气、气/水和气/固等界面作用后产生的复杂激波结构.和传统的分区与贴体变换方法不同,为Descartes网格包含多介质界面复杂流场计算提供新途径.

A moving planar shock interacting with multi-material interfaces in compressible fluid on fixed Descartes grids is studied.Level-set method combined with a revised real ghost fluid method（ r GFM） are applied for tracking gas-water and gas-solid interfaces,where a revised Riemann problem is constructed and its approximate solutions are populated for real and ghost fluid status. WENO schemes are employed for Euler and level-set equations. Numerical schlieren images are obtained for demonstrating shock evolution.Complex shock structures distinguish accurately and show various interfaces embedded in the fluid. Other than partition and coordinate transformation,we offer an approach for computation of complex flow field on Descartes grids involving multi-material interfaces or objects.