Critical assessment of the lattice Boltzmann method for cavitation modelling based on single bubble dynamics

The lattice Boltzmann Method (LBM) is recognised as a popular technique for simulating cavitation bubble dynamics due to its simplicity. In the validation of LBM results, the Rayleigh-Plesset (R-P) equation is commonly employed. However, most studies to date have neglected the impact of simulation settings on the predictions. This article sets out to quantify the impact of LBM domain size and bubble size, and the initial conditions of the R-P equations on the predicted bubble dynamics. First, LBM results were validated against the classical benchmarks of Laplace's law and Maxwell's area construction. LBM results corresponding to these fundamental test cases were found to be in satisfactory agreement with theory and previous simulations. Secondly, a one-to-one comparison was considered between the predictions of the LBM and the R-P equation. The parameters of the two models were matched based on careful considerations. Findings revealed that a good overlap between the predictions is observable only under certain conditions. The warming-up period of the LBM simulations, small domain size, and small bubble radius were identified as key factors responsible for the measured differences. The authors hope that the results will promote good simulation practices for cavitation simulation including both single bubbles and bubble clusters. Integrating different initial conditions from the lattice Boltzmann Method (LBM) into the Rayleigh-Plesset (R-P) equation shows notable difference results. The size of the domain and the distance between the centre of the circular bubble and its boundary are crucial factors in ensuring alignment between the results obtained from the LBM and the R-P equation. There is a approximately linear relationship between the radius of the bubble and the iteration at which the difference between the LBM and the R-P equation reaches a 5% threshold.