Research on Energy Dissipation of Hydrofoil Cavitation Flow Field with FBDCM Model

Abstract

In order to obtain a more detailed and comprehensive relationship between the cavitation phenomenon and energy loss, this paper takes an NACA66 hydrofoil as an example to analyze the specific relationship between the cavitation flow field and energy dissipation by using entropy production theory, a ZGB cavitation model, and k-ε turbulence model which were modified by a Filter-Based Density Correction model (FBDCM). The results show that the modified k-ε model can effectively capture the morphology of cavity evolution in the cavitation flow field. The vortex dilatation term contributes the most to the vorticity transport in cavitation flow. The energy loss of the cavitation flow field is primarily composed of turbulent dissipation, which is primarily distributed in the area below the lifted attached cavity and inside the vortex induced by the cloud cavity. The direct dissipation entropy production is predominantly distributed in the area near the stagnation point of the hydrofoil’s leading edge and inside the cavity. The wall entropy production is chiefly distributed in the area where the cavity is not covered. The cavitation entropy production mainly occurs on the vapor–liquid interface, and the value is negative, indicating that the vapor–liquid conversion in the cavitation process needs to absorb energy from the flow field.