Large-eddy simulation of the Richtmyer–Meshkov instability

Abstract

The subgrid-scale (SGS) terms of turbulence transport are modelled by the stretched-vortex SGS stress model, and a large-eddy simulation code multi-viscous fluid and turbulence (MVFT) is developed to investigate the MVFT problems. Then one AWE shock tube experiment of interface instability is simulated numerically by MVFT code, which reproduces the development process of the interface. The obtained numerical images of interface evolution and wave structures in flow field are consistent with the experimental results. The evolution of perturbed interface and propagation of shock waves in flow field and their interactions are analyzed in detail. The statistics features of turbulence mixing in the form of finer quantities, such as the turbulent kinetic energy, enstrophy, density variance, and turbulent mass flux are investigated, which also proves that the SGS model has a key role in large-eddy simulation. The turbulent kinetic energy and enstrophy decay with time as a power law.

Numerical investigations of interface instability and turbulent mixing driven by implosion

“…Wu等人 [34] 采用分子动力学方法模拟 研究了柱形汇聚冲击加载下铜-氦气界面导致的微观 尺度RM不稳定性增长规律. 本文作者在前期有关平面 冲击波加载下的界面不稳定性和湍流混合大涡模拟研 究基础上 [35][36][37][38][39][40][41][42][43][44][45] , 实现了三维球形汇聚几何中可压缩多 [46,47] 计算.…”

Interface Instability and Turbulent Mixing

“…Figure 6 shows the 3D calculated TMZ width [21] of Poggi's multi-mode shock tube experiment [22] with reshock in which the Mach number of incident SF 6 shock wave is 1.453, which impacts the SF 6 /air interface. Figures 7 [10] and 8 [23] show the calculated and experimental interface images of AWE'sS F 6 half-height and double-bump shock tube experiment [24,25], the Mach number of incident air shock wave is 1.26, respectively. Figure 9 [26] shows the SF 6 gas cylinder evolution at different times under the initial air shock wave with the Mach number 1.2, Figure 10 shows the width and height of gas cylinder at different times for experiment and numerical simulations.…”