水/气多介质问题的界面处理方法

针对不可压缩可压缩水/气多介质问题, 提出一种新的界面处理方法。在可压缩水/气界面处构造Riemann问题, 在水中设音速趋于无穷大, 求解Riemann问题得到不可压缩可压缩水/气界面处流体的准确流动状态; 然后以此状态结合GFM(ghost fluid method)方法分别为2种流体定义界面边界条件, 将两相流问题转化为单相流问题计算, 通过求解level set方程来跟踪界面的位置。对各种不同的界面边界条件定义方法进行了比较, 数值模拟结果表明算法能准确地捕捉各类间断的位置, 证明了算法的有效性和稳健性。

Interface treating methods for the gas-water multi-phase flows

A new interface treating method is presented for the compressible-incompressible gas-water multi-phase flow.The Riemann problem is constructed at the compressible gas-water interface, and then solved according to the hypothesis that the sound speed tends to infinity in the water.The solution of Riemann problem provides the fluid states for compressible gas and incompressible water at the interface.Those states can then be used to define the interface boundary condition by coupling the ghost fluid method.The level set method is employed to track the interface.The numerical examples of one-dimension case are given in this paper, furthermore, several comparisons are made with other results to verify the algorithm.Numerical results show that the provided algorithm can capture the discontinuities accurately, which demonstrates the robustness and efficiency.