The Study On R-M Instability Of The Material Interface In Gas-water Compressible Flow

The simulation of Richtmyer-Meshkov(R-M) instability of gas-water compressible flow is one of the difficulties of today's computation fluid dynamics. The physical phenomenon called R-M instability is defined that a material interface, which between two fluids with different density, will become instability when a shock wave crosses it, the turbulence will increase, and finally the two fluids will mix with each other strongly. The R-M instability has an important application on many fields such as inertial confinement fusion (ICF), Aviation and explosion. The key ideals of simulating R-M instability are capturing the moving material interfaces accurately and defining the interfacial boundary conditions reasonably.Compare to gas-gas compressible flow, the simulation of gas-water compressible flow is more difficult because the difference of physical properties between gas and water is very obvious. At present, the in-depth study of the R-M instability of gas-gas interface has been carried out by the correlative scholar on the world, but the study of gas-water interface is very little. So researching the R-M instability of gas-water interface is the main task of this paper, level set method is employed to capture the gas-water interfaces, real ghost fluid method (rGFM) is used to define the interfacial boundary conditions, spatial discretization of the Euler equations is via the fifth order WENO scheme and time discretization is via the third order TVD Runge-Kutta method, and then a Fortran code is developed and used to solve a series of gas-water compressible flow problems. For one-dimensional problems, the numerical solutions are close to the analytical results, which verify that the Fortran code is accurate and less problem-related. For two-dimensional problems, including a shock wave impacting on a cylindrical water mass, an underwater shock wave impacting on a gas bubble and underwater explosion, the reciprocity between shock wave, material interface and many kinds of discontinuities is captured clearly, the evolutionary process of material interface and increasing law of vorticity are given respectively by changing the intensity of incident shock wave, the simulation result is according with that in corresponding literature.