The investigation of RMI at an air/solid interface using Pagosa *

Richtmyer-Meshkov instability (RMI) occurs when there has a baroclinic generation of vorticity resulting from the misalignment of density and pressure gradients on a density-stratified interface. Accelerated by the incident shock, the interface becomes unstable, fingers grow to form bubbles of light fluid, while spikes are formed in heavy fluid. RMI is a key problem in many fields, such as deflagration-to-detonation transition (DDT) as well as inertial confinement fusion (ICF) and supernovae explosions. Therefore, its research is of scientific and engineering significance. This work will investigate the Richtmyer-Meshkov instability at a solid/air interface using a hydrocode Pagosa. We first verify the ability of Pagosa to handle the Rayleigh-Taylor instability (RTI) and the RMI at an air/SF₆ interface. Subsequently, we explore the RMI at a solid/air interface. The ultimate goal is to assess the effect of the initial perturbation (including the wavenumber, the amplitude etc) , the initial solid-gas ratio, the solid-material yield stress on the interface behavior.

Key words: Pagosa; RMI; Solid; Air; shock wave