Shock wave effects on hydrodynamic instability in elliptical bubbles

In this research work, the impacts of shock wave strengths on the hydrodynamic instability at elliptical light gas bubble are investigated numerically. The elliptical bubble is composed of helium gas, which is surrounded by nitrogen gas. Three different shock wave strengths are considered: Ms = 1.12, 1.25, and 1.5. Two-dimensional compressible Euler equations for two-component gas flows are simulated with an explicit modal discontinuous Galerkin solver. The present results reveal that the shock wave strength is critical in the growth of hydrodynamic instability at an elliptical light bubble. The shock wave strength causes significant changes in flow morphology, resulting in complex wave patterns, vorticity generation, vortex formation, and bubble deformation. In contrast to weak shock wave strength Mach numbers, strong shock wave strengths produce the larger rolled-up vortex chains, larger inward jet formation, and a stronger mixing zone with greater expansion. The effects of shock wave strengths are explored in detail through phenomena such as the vorticity production and evolution of kinetic energy, and enstrophy.