Numerical Simulation of Cavitation Bubble Collapse Near Wall

A finite-different method for gas-liquid two-phase flow such as cavitating flow with variable density is applied to investigate cavitation bubble collapsing behavior. The investigation of cavitation-bubble collapsing phenomena is very important to clarify the mechanism of damage on materials in hydromachine systems, in which the bubble collapse induces deformation and erosion on the surface of materials and causes reduction of durability of hydro-devices. The present method employs a finite-difference Runge-Kutta method and Roe's flux difference splitting approximation with the MUSCL-TVD scheme. A homogeneous equilibrium gas-liquid multi-phase model, which takes into account the compressibility of mixed media, is used. Therefore the present density-based numerical method permits simple treatment of the whole gas-liquid mixed flow field, including wave propagation, large density changes and incompressible flow characteristics at low Mach number. By applying this method, cylindrical bubbles located near solid wall and incident liquid shock wave are computed.