The numerical study of shock-induced hydrodynamic instability and mixing

Based on multi-fluid volume fraction and piecewise parabolic method(PPM), a multi-viscosity-fluid hydrodynamic code MVPPM(Multi-Viscosity-Fluid Piecewise Parabolic Method) is developed andapplied to the problems of shock-induced hydrodynamic interfacialinstability and mixing. Simulations of gas/liquid interfaceinstability show that the influences of initial perturbations on thefluid mixing zone (FMZ) growth are significant, especially at thelate stages, while grids have only a slight effect on the FMZ width,when the interface is impulsively accelerated by a shock wavepassing through it. A numerical study of the hydrodynamicinterfacial instability and mixing of gaseous flows impacted byre-shocks is presented. It reveals that the numerical results are ingood agreement with the experimental results and the mixing growthrate strongly depends on initial conditions. Ultimately, the jellylayer experiment relevant to the instability impacted by explodingis simulated. The shape of jelly interface, position of front faceof jelly layer, crest and trough of perturbation versus time aregiven; their simulated results are in good agreement withexperimental results.