Influence of high-frequency micro-vibrations on hydrofoil vortex shedding

Hydrofoils are widely used in marine applications, and significant progress has also been made in the study of their fluid-structure interaction. However, in practical applications, high-frequency micro-vibrations (above tens of Hz, with micrometer-scale vibrations) induced by ship propulsion systems can still alter the vortex shedding behavior and wake dynamics of hydrofoils. This study systematically analyzes the lock-in mechanism between structural vibrations and vortex shedding by combining smart actuators (MFC) with a hydrofoil and observing changes in the flow field. Through a combination of simulations and experiments, we investigate key physical mechanisms such as the amplitude and phase variations of pressure and velocity during the lock-in process, as well as the energy transfer process. Additionally, the phenomenological model provides a theoretical explanation for the lock-in mechanism.These findings provide important insights into the development of fluid-structure interaction analysis for underwater structures such as hydrofoils, propeller blades, and rudders, and offer potential solutions for flow control applications in marine engineering.