Study of cavitation bubble collapse near a rigid boundary with a multi-relaxation-time pseudo-potential lattice Boltzmann method

Due to the complex phase change and heat transfer processes, the mechanisms of cavitation bubble collapse near a rigid boundary are well recognized to be complicated. Based on a modified large-density ratio multi-relaxation-time pseudo-potential lattice Boltzmann model, a single and a dual cavitation bubble collapse process near a rigid boundary with large-density and various viscosity ratios are simulated in the present study. Effects of density ratio, viscosity ratio, initial pressure difference, and distance between the cavitation bubble and wall on the cavitation process are studied. Furthermore, the evolution of maximum pressure, micro-jet velocity, lifetime, deformation index, and the first introduced total kinetic energy of cavitation bubbles are analyzed in the development of cavitation. Simulations show that the interaction mode of the bubbles and the distance between the rigid boundary and the lower bubble are key factors in determining the effect of aeration reduction. The study also shows that the proposed lattice Boltzmann pseudo-potential model is a robust and effective tool for studying the collapse of near-wall cavitation bubbles and has potential to predict the interaction of cavitation bubbles in the presence of complex boundaries.