EXPLORATION AND RESEARCH OF THE IMPACT OF HYDROFOIL SURFACE WATER INJECTION ON CAVITATION SUPPRESSION

摘要

To explore the impact of hydrofoil surface water injection on cavitation suppression, the unsteady cavitation flow around the NACA0066 hydrofoil was simulated by the modified RNG k-ε turbulence model combined with the full-cavitation model. The influence of water injection position and jet angle on cavitation suppression were analyzed. A detailed analysis shows that cavitation suppression effect is closely related to water injection position and jet angle. It is noted that the optimal position is just the vertex position on the upper surface of hydrofoil. Water injection in an appropriate position will increase the velocity gradient in the boundary layer and enhanced the ability of anti reverse pressure gradient, thus weakening the intensity of separation flow. The recirculation zone thickness and the velocity of re-entrant jet are all significantly reduced. For the study of jet angle, the cavitation suppression effect is obvious with jet angles from 145° to 155°. This may due to the high pressure produced by the mixing of jet with the main flow, and the high-pressure zone limit the spread of low pressure from the leading edge to the trailing edge of hydrofoil. This can also explain why the suppression effect is significant at the vertex position on the upper surface.