Numerical investigation of Richtmyer–Meshkov instability in shock accelerated finite thickness fluid layer with particles

Richtmyer–Meshkov instability in shocked fluid layer with particles is numerically investigated. Six different types of fluid layer are set up to facilitate the exploration of the effect of the presence of particles and the effect of the initial thickness of the fluid layer on the Richtmyer–Meshkov instability relating to fluid layer. The interface morphology has been affected by the large particles ($d$ = $40\mu m$), leading to many “wrinkles” being formed on the interface II₁, while the interface II₁ and interface II₂ under smaller particles ($d$ = $5\mu m$ and $d$ = $20\mu m$) bear a strong resemblance to the case without particles. Moreover, the interface-coupling effect can have a certain impact on the evolution of the interface in narrow fluid layer. The presence of particles will increase the development of the mixing width during the passage of reflected shock wave due to the enhanced disturbance caused by particles and inhibit the growth of the mixing width at the late stage for the inhibition of the interface motion caused by particles. A similar RM instability evolution of small particles ($d$ = $5\mu m$) has be found, however, with a discernible lag behind the carrier fluid, which is ascribed to the particle inertia. Moreover, particle concentration characteristics and classical structures such as spikes and jets manifest in the evolution of interfaces as well.