Two-way 연성을 고려한 기포 캐비테이션의 수치 모델링

Abstract

This paper deals with a numerical simulation for two-way interaction of single bubbles with viscous flows about a body. The viscous flows and the bubble dynamics are analyzed by a combined Lagrangian approach. Starting with a presumably steady flow without bubbles that is computed by using the Lagrangian vortex method, the bubbles are tracked following the Newton's 2nd law. The ambient pressure field stimulates the variation of spherical bubble size which is governed by the Rayleigh-Plesset equation. We include the effect of bubbles on the flow field by modelling the drag acting on individual bubble as a pair of shedding vortices equivalent to the impulse change of the drag. And the bubble is replaced with a pulsating source. With a refinement of the PSE scheme for viscous diffusion, more consistent results are obtained: the evolution of vortical flow structures around an NACA0012 for Re=1200 has good agreement with that of the experimental results. It is observed that the simulation with the two-way coupling is significantly different in the bubble behavior from the one-way coupling simulation. The present modelling would be applicable to analysis of the bubble cavitation.