Comparative Study on Cavitation Characteristics and Mechanisms of the NACA0015 Hydrofoil under Rotating and Stationary Conditions

Cavitation characteristics in rotating hydrofoils are crucial for rotating machinery performance. The flow dynamics, significantly influenced by system rotation, differ fundamentally from stationary hydrofoils and require in-depth investigation. This study aims to elucidate the cavitation mechanism of rotating hydrofoils by comparing their characteristics with stationary hydrofoils, focusing on the impact of cavitation number and rotational effects. The research combined numerical simulation and experimental validation. Simulations employed the RNG k-ε model, a mixture model, and the Z-G-B cavitation model for a NACA0015 hydrofoil. Experiments used a rotating disc platform with high-speed photography to capture cavity morphology and surface coating to assess erosion. Compared to a stationary hydrofoil, the rotating foil exhibited less degradation in hydrodynamic performance as the cavitation number decreased. The cavity volume on the rotating foil was significantly larger and its temporal evolution more gradual. The area of the low-pressure zone on the suction surface was also substantially larger for the rotating configuration. The cavitation mechanism of a rotating hydrofoil is governed by the synergistic effect of centrifugal and Coriolis forces, which create a distinct three-dimensional flow field. This leads to markedly different cavitation dynamics, including mitigated performance loss and enhanced cavity development, compared to the two-dimensional characteristics of a stationary hydrofoil.