Numerical investigation on the cavitation instability induced by local collapse around a 2D CLARK-Y hydrofoil

Abstract In this study, a two-phase flow solver with phase change is improved with considering the compressibility and is implemented in the open source software OpenFOAM. The thermal effect between water and vapor is ignored and the barotropic fluid hypothesis is used to close the system of Navier-Stokes equations. The finite volume method (FVM) is utilized for discretization and the volume of fluid (VOF) method is employed to capture the water/vapor interface. The improved solver is applied to the cavitating flow around a 2D CLARK-Y hydrofoil. The numerical results show good agreement with the experimental results. The mechanism of the cavitation instability induced by the re-entrant jet can be well reproduced. Pressure waves propagation induced by the collapse of the local shedding cloud cavity are discussed, which might lead to the shrinkage of the surrounding cavitation and high pressure pulse to the hydrofoil surface. The different roles played by the re-entrant jet and the local cavity collapse at different instants over one period in the compressible fluids are analyzed. Finally, analyses of the interaction between the cavity and the vortex structures are conducted.