Study on the Collapse Process of Cavitation Bubbles Including Heat Transfer by Lattice Boltzmann Method

Yang Liu,Yong Peng

doi:10.3390/jmse9020219

Abstract

In this study, an improved double distribution function based on the lattice Boltzmann method (LBM) is applied to simulate the evolution of non-isothermal cavitation. The density field and the velocity field are solved by pseudo-potential LBM with multiple relaxation time (MRT), while the temperature field is solved by thermal LBM-MRT. First, the proposed LBM model is verified by the Rayleigh–Plesset equation and D2 (the square of the droplet diameter) law for droplet evaporation. The results show that the simulation by the LBM model is identical to the corresponding analytical solution. Then, the proposed LBM model is applied to study the cavitation bubble growth and collapse in three typical boundaries, namely, an infinite domain, a straight wall and a convex wall. For the case of an infinite domain, the proposed model successfully reproduces the process from the expansion to compression of the cavitation bubble, and an obvious temperature gradient exists at the surface of the bubble. When the bubble collapses near a straight wall, there is no second collapse if the distance between the wall and the bubble is relatively long, and the temperature inside the bubble increases as the distance increases. When the bubble is close to the convex wall, the lower edge of the bubble evolves into a sharp corner during the shrinkage stage. Overall, the present study shows that this improved LBM model can accurately predict the cavitation bubble collapse including heat transfer. Moreover, the interaction between density and temperature fields is included in the LBM model for the first time.

Highlights

The present study shows that this improved lattice Boltzmann method (LBM) model can accurately predict the cavitation bubble collapse including heat transfer
The pseudo-potential LBM-multiple relaxation time (MRT) model was used for density and velocity fields, while thermal LBM-MRT model was used for the temperature field
For the density and velocity fields, a multiple relaxation time [14,40] was coupled with the LBM model (LBM-MRT), and a force scheme improved by Li et al [17] was included into the model

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Cavitation is a normal phenomenon in hydraulic and marine engineering. The cavitation bubble always exists around the water turbines, hydrofoils and ship propellers [1]. The collapse of a cavitation bubble will generate extremely high pressure and temperature and this characteristic will cause great harm to the surrounding structures. The intense power of the cavitation bubble collapse can be utilized to increase the drilling rate of oil. It is very important to show the collapse process of the cavitation bubble and its interaction with the structures

Methods

Results

Conclusion