Study of cavitation inception using multiphase lattice Boltzmann method with incorporating equations of state

Abstract

The study of cavitation inception is crucial in several hydraulic machines, e.g. pumps, nozzles and sprays. In the present study, a multiphase lattice Boltzmann method (LBM) is implemented for simulation of the cavitation bubbles dynamics and characteristics of cavitating flows. The effect of employing various equations of state (EoS) is investigated on the computing of interaction forces and the phase separation between the liquid and its vapor in the cavitating flows. Herein, the cubic EoSs of Shan-Chen (SC) and Carnahan-Starling (CS) and the non-cubic EoS of Peng-Robinson (PR) are applied. The exact difference method is imposed to improve the numerical stability for simulation of two-phase flow systems. The accuracy and efficiency of the present method are examined by comparison of the results obtained for the homogeneous and heterogeneous cavitation with those of reported in the literature. Then, the implemented multiphase LBM is used for studying the inception and growth of the cavitation bubbles in the throat of a venturi. The effect of hydrophobicity and hydrophobicity of the nozzle wall on the cavitation dynamics is investigated and a detail discussion is made for the results from the numerical and physical point of view. Evaluation of the present results shows that the multiphase LBM with incorporating an appropriate equation of state has excellent capability for prediction of the bubble dynamics and cavitating flow characteristics in applied geometries.