COMPUTATIONAL SIMULATION OF CAVITATION BUBBLE COLLAPSE

: Cavitation threatens lifetime of hydraulic machines, ship propellers or diesel injection nozzles, but can also serve as efficient way of pathogenic microorganisms eradication, water disinfection and chemical residuals removal. While classical Rayleigh-Plesset equation provides suitable 1D tool for description of the bubble behavior away from the wall, it suffers serious problems close to solid boundary due to its assumption of bubble sphericity during all stages of the bubble life. Therefore, a detail computational simulation based on RANS equations and multiphase Volume of Fluid approach was performed. Simulation was able to capture microjet, which deforms the bubble in solid wall vicinity, penetrates through bubble interior and is responsible for transformation from vapor bubble to vapor ring. It is important that numerical solution enabled detailed spatial description of the bubble evolution and allowed to distinguish between the pressure peaks caused by microjet impact on the wall and bubble collapse, thereby enhancing our understanding of the bubble collapse close to the solid boundary.