Numerical study on shock–bubble interaction in a compressible fluid based on boundary element method

The interaction between shock waves and bubbles significantly alters the dynamic characteristics of the bubbles and the flow field. This paper employs the boundary element method to establish the boundary integral equation for compressible fluid by solving the wave equation. For toroidal bubbles penetrated by the jet, the single connectivity of the fluid domain is ensured by adding cutting lines, with the effect of the shock wave coupled into the Bernoulli equation. In addition, the auxiliary function method is used to calculate the flow field pressure to avoid large computational errors due to the discontinuity of the velocity potential. In this study, we analyze the dynamic characteristics of bubbles in a compressible flow field under the action of shock waves over two oscillation periods and compare the results with those in an incompressible flow field. On this basis, we further investigate the energy loss mechanism of the bubble in the compressible flow field. Finally, we conduct a parametric analysis. The research results indicate that the bubble energy loss is the greatest near the minimum bubble radius, and almost all the energy generated by the shock wave is radiated outward. As the peak shock wave pressure and the temporal decay constant increase, the maximum pressure at the flow field measurement point gradually increases; as the bubble initial uniform pressure increases, the maximum jet velocity of the bubble gradually decreases; when the bubble's action radius equals 0.4, the shock wave and bubble interaction produce the most pronounced effect.