基于格子Boltzmann方法的空泡溃灭过程模拟

Simulation of cavitation collapse process based on lattice Boltzmann method

针对自由边界的三维空泡溃灭问题,以格子Boltzmann方法为流场核心求解器,结合伪势多相流模型与Carnahan-Starling(C-S)状态方程,开展了定压边界条件下,不同温度、初始溃灭半径的三维空泡溃灭过程的模拟研究.通过模拟给出了空泡溃灭过程中流场的两相界面图,并定量分析了三维空泡溃灭时间随着半径变化的关系.结果表明:在定压强边界下,空泡的初始半径与总溃灭时间呈线性相关,且不同温度、不同初始半径的空泡溃灭具有相似的过程;相同温度条件下,空泡溃灭速度随时间不断增加,空泡初始半径越大,空泡溃灭速率最大值出现的时间越晚;对于相同半径条件下,温度比越大,空泡溃灭最大速率出现的时间越晚.

To solve the problem of three-dimensional bubble collapse with free boundary condition,the lattice Boltzmann method,combined with pseudo potential multiphase flow model and Carnahan-Starling(C-S)equation of state,was employed as the flow field core solver.Simulation of three-dimensional bubble collapse process was performed at different temperatures and initial collapse radius under constant pressure boundary conditions.The density and pressure contour diagram of the flow field in the process of cavitation collapse were given by simulation,and the relationship between the three-dimensional cavitation collapse time and the radius was quantitatively analyzed.Results show that the initial radius of cavitation is linearly correlated with the total collapse time under constant pressure boundary,and the collapse process of cavitation with different temperatures and initial radius is similar.Under the same temperature condition,the cavitation collapse speed increases with time,and the larger the initial cavity radius,the later the maximum cavity collapse speed occurs.Under the same radius condition,the larger the temperature ratio,the later the maximum cavitation collapse speed appears.