Numerical Simulation of Collapsing Vapor Bubble Clusters Close to a Rigid Wall

Numerical simulation is a promising way for improvement of physical insight into collapse dynamics for clouds with strong bubble-bubble interaction. The current study adopts the theory proposed by Brennen et al [6] based on “cloud interaction parameter”, although the theory is a simplification of realistic cloud collapses, it shows main features, such as shock focusing and enhancement of the resulting shock strength. We offer high quality CFD Simulations of collapsing vapor-bubble clouds close to a rigid wall. The simulations contain physical details such as wave dynamics, bubble deformation and vapor bubble rebound. The simulation time captures several sequential collapses. Our results show different collapse structures as well as different interaction mechanisms of bubbles. We present focusing features as well as unfocused collapses and discuss their effects on material loads. . Increasing the interaction parameter leads to an enhancement of the collapse pressure of individual bubbles, enhanced vapor production during rebound and enhanced load at the wall. An increase in stand-off distance changes the collapse dynamics significantly. Depending on the interaction, rebounds may occur close to the wall, leading to intense secondary collapses.