Rayleigh-Taylor instability under multimode perturbation:Discrete Boltzmann modeling with tracers  

作　　者：Hanwei Li Aiguo Xu Ge Zhang Yiming Shan 

机构地区：[1]Laboratory of Computational Physics,Institute of Applied Physics and Computational Mathematics,Beijing 100088,China [2]HEDPS,Center for Applied Physics and Technology,College of Engineering,Peking University,Beijing 100871,China [3]State Key Laboratory of Explosion Science and Technology,Beijing Institute of Technology,Beijing 100081,China [4]Energy Resources Engineering Department,Stanford University,367 Panama St,Stanford,CA 94305-2220,United States of America

出　　处：《Communications in Theoretical Physics》2022年第11期180-198,共19页理论物理通讯（英文版）

基　　金：supported by the National Natural Science Foundation of China(under Grant No.12172061);the Opening Project of State Key Laboratory of Explosion Science and Technology(Beijing Institute of Technology)under Grant No.KFJJ21-16 M;Foundation of Laboratory of Computational Physics。

摘　　要：The two-dimensional Rayleigh-Taylor Instability(RTI)under multi-mode perturbation in compressible flow is probed via the Discrete Boltzmann Modeling(DBM)with tracers.The distribution of tracers provides clear boundaries between light and heavy fluids in the position space.Besides,the position-velocity phase space offers a new perspective for understanding the flow behavior of RTI with intuitive geometrical correspondence.The effects of viscosity,acceleration,compressibility,and Atwood number on the mixing of material and momentum and the mean nonequilibrium strength at the interfaces are investigated separately based on both the mixedness defined by the tracers and the non-equilibrium strength defined by the DBM.The mixedness increases with viscosity during early stage but decreases with viscosity at the later stage.Acceleration,compressibility,and Atwood number show enhancement effects on mixing based on different mechanisms.After the system relaxes from the initial state,the mean non-equilibrium strength at the interfaces presents an initially increasing and then declining trend,which is jointly determined by the interface length and the macroscopic physical quantity gradient.We conclude that the four factors investigated all significantly affect early evolution behavior of an RTI system,such as the competition between interface length and macroscopic physical quantity gradient.The results contribute to the understanding of the multi-mode RTI evolutionary mechanism and the accompanied kinetic effects.

关 键 词：Rayleigh-Taylor instability multi-mode perturbation Discrete Boltzmann modeling tracers non-equilibrium effects kinetic modeling 

分 类 号：O357.5[理学—流体力学]