Abstract:Cavitation often causes noise, vibration and corrosion of hydraulic mechanical components such as ship propellers, pumps, and turbines, and causes the overall performance of the equipment to be greatly reduced, or even destroyed. Therefore, it is of great significance to carry out cavitation flow control. The method of arranging injection water holes on the suction side of the hydrofoil can effectively block the reentrant jet to suppress cavitation. Through the highspeed visual flow field test technology, the cavitation morphology of NACA66 (MOD) original hydrofoil and jet hydrofoil surfaces was obtained. The influence of jet control parameters on cavitation suppression was studied, and the adaptability of active jet to cavitation flow control under varying operating conditions was analyzed. It was found that under different cavitation conditions, the active jet significantly reduced the cavity length around the suction surface of the hydrofoil, and the cavitation suppression effect was significant. When the jet coefficient and jet position were different, the effect of cavitation flow control was also different. In the cloud cavitation stage, the jet of 0.19 chordlength position from the leading edge of the hydrofoil (H1 model) can achieve the best cavitation suppression effect, and it was always better than that of the H2 model in the range of cavitation number σ≤1.28. In the sheet cavitation stage, σ>1.44, the jet of 0.45 chordlength position from the leading edge of the hydrofoil (H2 model) was more effective in suppressing cavitation. When the fixed jet position (H1 model) and jet flow rate (flow coefficient was 0.0245), simplified flow control process, during the continuous development of cavitation (cavitation number was with 0.83≤σ≤1.46), the cavitation suppression effect was relatively stable, the deviation from the best suppression effect was within 0.06, which showed that the H1 model had good adaptability to working conditions. The research results provided a direction for exploring the active control technology of cavitation flow.
