Numerical Investigation of Weak Planar Shock—Elliptical Light Gas Bubble Interaction in Shock and Reshock Accelerated Flow

The computational results of the weak planar shock–elliptical light gas bubble interaction are presented. The influence of different light gases (helium and neon) on the interaction process is clarified using high-resolution computation schemes. It is found that the helium gas bubble is easier to be compressed than the neon gas bubble owing to its smaller density and the helium gas bubble can be split into two, upper and lower, parts by the inward air jet, which is not the case for the neon gas bubble. The area of the helium gas bubble decreases in the incident and reflected shock compression stages and increases in the expansion stages behind the shock waves. At the same time, the neon gas bubble area decreases in the four stages, which is mainly due to the fact that the average vorticity intensity increases, as the gas density decreases. Further, the factors affecting the vorticity evolution are also analyzed and it is revealed that the compression term has a relatively stronger influence on the vorticity evolution than the other two terms in the helium and neon gas bubbles, but in the expansion stage behind the incident shock the influence of viscosity is stronger than the baroclinic effect in the neon gas bubble.