Wall pressure amplification of shock-collapsed multi-bubble arrays near a rigid wall

This numerical study investigates the collapse of various arrangements of gas bubbles immersed in water in the vicinity of a rigid wall and impacted by a planar shock wave. Multiple bubble configurations, from 2 to 5 bubbles, are compared, focusing primarily on the pressure loads on the wall and the potential amplification in comparison with the single-bubble case. The three-dimensional simulations are performed using a massively parallel compressible diffuse interface solver. The effects of the grid resolution and the mass transfer term are discussed. The main characteristics of the flows are described, and the dynamic behaviors in pressure wave propagation are illustrated. A power-law is proposed for the evolution of the maximum pressure peak on the wall as a function of the density ratio of the bubble array. An amplification of a factor 30 is highlighted for a pyramidal arrangement.