Numerical Simulation of Bubble Dynamics in a Vortex Flow Using Navier- Stokes Computations and Moving Chimera Grid Scheme

A numerical scheme using Navier-Stokes computations was applied to simulate bubble dynamics in a vortex flow. A moving grid generation scheme and a Chimera grid scheme were integrated with the Navier-Stokes solver to automatically generate the appropriate grids based on the moving bubble surface. A general free surface boundary condition was implemented to describe the bubble surface motion. The numerical scheme was validated by comparing results with those obtained from the Rayleigh-Plesset equation and from the potential flow solver, 3DynaFS, for bubble dynamics in an infinite volume of quiescent water with/without the gravity effect. Imp ortant numerical factors that influenced the accuracy of solution are reported. Finally, the computations were conducted for bubbles released within a Rankine vortex. Different bubble behaviors were observed for different cavitation numbers.