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

Abstract

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.

A lattice Boltzmann study of the thermodynamics of an interaction between two cavitation bubbles

“…In addition, the nonlinear and time-dependent behavior during the bubble evolution process can require significant computational resources [17]. The pseudo-potential lattice Boltzmann method (LBM), which uses a pseudo force to mimic the interaction force between particles, can automatically produce the gas-liquid interface and has become one of the most widely-used LBM multiphase models in the last three decades due to its simplicity and sufficient accuracy [24,25,26,10,40,41,32,42,49]. Thermal pseudo-potential LBMs can be categorized into two kinds: the hybrid model and the double-distribution-functions (DDF) model.…”

“…Numerous studies have been carried out to simulate the growth or collapse processes of cavitation bubbles with pseudo-potential LBM [25,40,41,39,37,38,51,52,1,20,21,50,19,22], but most of these studies have simulated only the growth or collapse processes. In all the LBM-based cavitation bubble inception or growth studies, a vapor nucleus is initialized, and the bubble is formed by nucleus growth under the pressure difference between the bubble and the surrounding liquid [39,37,48,12].…”