Investigation on the dynamic behavior of cloud cavitation around a flexible hydrofoil

The objective of this paper is to investigate the dynamic behavior of cloud cavitating flow around a flexible hydrofoil with experimental and numerical methods. The tightly coupled fluid-structure interaction (FSI) modeling is applied and validated with the experimental data. The Q - criterion and ω - criterion are applied to illustrate the interaction between the vortex structures and cavities. The flexibility is seen to result in nose-up twist deformation, causing a reduction of the shedding frequency from an increase in the attached cavity length. Due to the flexibility, the fluctuation of load coefficients of the flexible hydrofoil is larger than that of the rigid hydrofoil. Moreover, the re-entrant jet propagation speed of the flexible hydrofoil is greater than that of the rigid hydrofoil. The shed cloud cavity is observed to be uniform along the flexible hydrofoil span under the combined influence of the strong vibration and the gap flow.