Rayleigh-Taylor不稳定性的MPS数值模拟

Numerical Simulation of Rayleigh-Taylor Instability with MPS Method

移动粒子半隐式法(MPS法)是一种适用于不可压缩流体流动计算的无网格粒子法,它采用完全的拉格朗日描述定义流体的运动,将流体离散为可移动的粒子,流体控制微分方程转化为粒子间的相互作用。本文采用MPS法对Rayleigh-Taylor不稳定性进行了二维数值模拟。结果表明,在不稳定性发展的前期阶段,当扰动振幅远远小于扰动波长时,流体界面的小扰动具有指数增长形式,与经典的线性理论分析结果一致。非线性发展阶段,所得到的气泡和尖钉的部分特征与实验结果相吻合。

As a meshless method,the Moving Particle Semi-Implicit Method is used to calculate the in-compressible fluid flow. The fluid is represented by a set of moving particles with full Lagrange description,and the differential operators in governing equations are discretized to the interactions of particles. With this method,two-dimensional Rayleigh-Taylor Instability (RTI) is simulated. It is demonstrated that,when the amplitude is much smaller than the wave,the perturbation of interface grows exponentially at early stage of the instability,which is consistent with the linear theory. During non-linear stage,the characteristics of bub-bles and strikes obtained in the calculation agrees with the previous experiment to some extent.