Several compressible computational fluid dynamics methods applied to transient sheet/cloud cavitation

This paper introduces several compressible computational fluid dynamics (CFD) methods and assesses their ability to simulate typical sheetto-cloud cavitating flow around a hydrofoil. More precisely, the Tait equation of state is used to describe the density of water, while the ideal gas equation of state is used to model the density of vapor. The first method assumes that the cavitation is a multiphase flow with isothermal conditions, meaning that it exhibits isothermal compressibility. Based on the first method, the second and third methods take into account the thermal energy and total energy equations, respectively, i.e., the thermal energy compressibility and the total energy compressibility. An incompressible simulation is also performed for the comparison. The results show that all of the strategies successfully replicate the periodic breakup of the sheet cavity and the formation of the cloud cavity. The predicted frequency of cavity shedding using compressible methods is higher than that using the incompressible method. In addition, all the CFD simulations confirm that the disturbance moving upward in the sheet cavity is actually a condensation shock. The overpressure resulting from the collapse of the cavity can be captured using three compressible approaches. The boundary layer and time-averaged hydrofoil pressure coefficient are compared and analyzed, revealing a negligible difference among the three compressible simulation results.