摘要：The objective of this article is to investigate the flow structure of the ventilated cavitation around an under-water vehicle. In the experiments, a high-speed camera system is used to observe cavity evolution of the unsteady cavitation flow, the velocity field is measured by the particle image velocimetry technique, and dynamic pressure measurement systems are used to measure pressure fluctuations under different cavitation numbers. We seek to investigate the mechanism of the re-entrant flow and shock wave phenomenon during the cavity evolution. The study concludes that the ventilated cavity is insufficient to overcome the re-entrant jet intrusion and the re-entrant jet moves upstream straightly as well as curvilinearly. Then, the vortex structure rotating clockwise forms on the vehicle surface and the cavity area with low velocity represents the vortex. The re-entrant jet rolls back after the re-entrant jet reaches the front of the cavity. The experimental results also show that the pressure signals at different instants destabilize on the vehicle surface; fluctuant pressure peak is detected at the closure region of the cavity and pressure peak increases as the cavitation number is decreased. Surface pressure fluctuations travel on the vehicle surface from the collapse of cloud cavitation. The variation in shedding frequency for different cavitation numbers is discussed at the end of the article.
