Numerical investigation of the Richtmyer-Meshkov instability for the vapor-liquid interface with phase change

<p indent="0mm">In this paper, using a recently proposed sharp-interface method for compressible multiphase flows with phase change, we numerically study the Richtmyer-Meshkov instability problem of the vapor-liquid interface, both with and without phase change. The wave structures and the interfacial evolution mechanism of a single-mode sinusoidally perturbed interface under the impact of a shock wave are analyzed. First, the classical air-SF6 interface Richtmyer-Meshkov instability and shock water column interaction are simulated in the paper to validate the feasibility of the numerical method. The numerical simulations and experimental results are generally in good agreement, indicating that the present method can accurately capture the interface flow evolution characteristics during the development of Richtmyer-Meshkov instability. Next, we investigate the similarities and differences in Richtmyer-Meshkov instability at the vapor-liquid interface under thirteen conditions: no phase change, evaporation, and condensation with three different Mach numbers. It is shown that, unlike the air-SF6, a double spike structure is formed during the development of interfacial instability due to the large acoustic impedance difference at the vapor-liquid interface. And the phase change process affects the local deformation of the interface, as the evaporation effect inhibits the development of the interfacial instability, while the condensation effect promotes the development of the interfacial instability. Finally, we compare the numerical simulation data with the existing linear model and find that the impulsive model can predict the linear growth of the early stage, while the nonlinear growth of the later stage will be investigated further.