Numerical study of the Richtmyer-Meshkov instability induced by non-planar shock wave in non-uniform flows

The effects of non-uniformity of flows and initial disturbance intensity of the incident shock wave on Richtmyer-Meshkov instability (RMI) when a sinusoidal shock wave with Ma = 1.25 impinging an unperturbed interface are numerically investigated. The interface morphology, turbulent mixing zone width (TMZW), Y-integrated vorticity, circulation, and turbulent kinetic energy (TKE) are qualitatively and quantitatively compared before and after reshock. The numerical results indicate that the non-uniformity of flows and initial disturbance intensity of sinusoidal shock wave are significant factors of RMI evolution. On the one hand, the TMZW and its growth rate increase with the decrease of the parameter of non-uniformity before reshock; while, those discrepancies are reduced after reshock. On the other hand, the increase of the initial disturbance intensity of sinusoidal shock wave leads to the increase of the vorticity, circulation and TKE, the TMZW and it growth rate increase accordingly, all the time. Further analysis points out that the TMZW evolves with time as a power law before reshock, and the value of theta is sensitive to the initial conditions. After reshock and the first reflected rarefaction wave, the TMZW grows in time as a negative exponential law , but t* is different for the two stages.