Numerical study on Rayleigh-Taylor effect on cylindrically converging Richtmyer-Meshkov instability

作     者：ZhiGang Zhai Fu Zhang ZhangBo Zhou JuChun Ding Chih-Yung Wen 

作者机构：Department of Modern MechanicsUniversity of Science and Technology of ChinaHefei 230026China Beijing Institute of Space Long March VehicleBeijing 100076China Department of Mechanical EngineeringThe Hong Kong Polytechnic UniversityHong Kong 999077China 

出 版 物：《Science China(Physics,Mechanics & Astronomy)》 (中国科学：物理学、力学、天文学（英文版）)

年 卷 期：2019年第62卷第12期

页      面：68-77页

核心收录：

学科分类：080704[工学-流体机械及工程] 080103[工学-流体力学] 08[工学] 0807[工学-动力工程及工程热物理] 0801[工学-力学（可授工学、理学学位）] 

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.11772329,11802304,and U1530103) the Science Challenge Project(Grant No.TZ2016001) the Research Grants Council,Hong Kong(Grant No.152151/16E) 

主　　题：converging shock wave Rayleigh-Taylor effect Richtmyer-Meshkov instability 

摘      要：Evolution of a two-dimensional air/SF6 single-mode interface is numerically investigated by an upwind CE/SE method under a cylindrically converging circumstance. The Rayleigh-Taylor effect caused by the flow deceleration on the phase inversion(RTPI)is highlighted. The RTPI was firstly observed in our previous experiment, but the related mechanism remains unclear. By isolating the three-dimensional effect, it is found here that the initial amplitude(a0), the azimuthal mode number(k0) and the re-shocking moment are the three major parameters which determine the RTPI occurrence. In the variable space of(k0, a0), a critical a0 for the RTPI occurrence is solved for each k0, and there exists a threshold value of k0 below which the RTPI will not occur no matter what a0 is. There exists a special k0 corresponding to the largest critical a0, and the reduction rule of critical a0 with k0 can be well described by an exponential decay function. The results show that the occurrence of the RTPI requires a small a0 which should be less than a critical value, a large k0 which should exceed a threshold, and a right impinging moment of the re-shock which should be later than the RTPI occurrence. Finally, the effects of the incident shock strength, the density ratio and the initial position of the interface on the threshold value of k0 and on the maximum critical a0 are examined. These new findings would facilitate the understanding of the converging Richtmyer-Meshkov instability and would be helpful for designing an optimal structure of the inertia confinement fusion capsule.