Instability in shocked granular gases

18th APS-SCCM; 24th AIRAPT

Sirmas, Nick^1 ; Falle, Sam^2 ; Radulescu, Matei^1

Department of Mechanical Engineering, University of Ottawa, ON

K1N6N5, Canada^1

Department of Applied Mathematics, University of Leeds, Leeds

LS2 9JT, United Kingdom^2

关键词: Discrete particle models;    Discrete particle simulation;    Higher frequencies;    Higher order effects;    Impact velocities;    Inelastic collision;    Non-uniformities;    Shock compressions;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/500/15/152014/pdf
DOI  :  10.1088/1742-6596/500/15/152014

来源: IOP

【 摘 要 】

Shocks in granular media, such as vertically oscillated beds, have been shown to develop instabilities. Similar jet formation has been observed in explosively dispersed granular media. Our previous work addressed this instability by performing discrete-particle simulations of inelastic media undergoing shock compression. By allowing finite dissipation within the shock wave, instability manifests itself as distinctive high density non-uniformities and convective rolls within the shock structure. In the present study we have extended this work to investigate this instability at the continuum level. We modeled the Euler equations for granular gases with a modified cooling rate to include an impact velocity threshold necessary for inelastic collisions. Our results showed a fair agreement between the continuum and discrete-particle models. Discrepancies, such as higher frequency instabilities in our continuum results may be attributed to the absence of higher order effects.