Experimental investigation of tip vortex cavitation using a stationary partial propeller blade model

Propeller cavitation is a highly complex phenomenon involving multiphase flow structures. Detailed observation of cavity behavior in localized regions is essential for safe and efficient propeller design. Partial blade models allow for focused investigation of specific blade angles and operating conditions, with a relatively larger observation frame than conventional cavitation tunnel tests. This study investigates the tip vortex flow characteristics of a full-scale propeller using two stationary partial blade models with different section shapes and cambers. The experiments were conducted under operating conditions corresponding to ship speeds of 16–18 knots and cavitation numbers ranging from 0.51 to 0.36. Several important physical phenomena were observed, such as the collapse of cavitation bubbles triggered by re-entrant flow and the complex interactions between primary and secondary vortex cavities. In particular, the high-speed imaging analysis clearly visualizes the collapse process of cavitation bubbles caused by the re-entrant flow in the blade tip region. The analysis showed that, at a cavitation number of 0.42, the two models exhibited a difference of approximately 28%. The study identifies the formation of primary and secondary vortex cavities, clarifies the process by which they interact and grow together, and provides insight into how the adverse effects of tip vortex cavitation can be effectively mitigated.