Numerical simulation of the vortex shedding and lock-in phenomenon of an active vibration hydrofoil

Hydrofoils are widely applied in the maritime domain, and their vibrational characteristics significantly influence the genesis and evolution of vortices. Consequently, modulating vortex shedding through the active vibration of hydrofoils may lead to the enhancement of the hydrodynamic performance of bluff bodies. In order to study the influence of structural oscillations on vortex shedding, both Computational Fluid Dynamics (CFD) and wake oscillator models were used to simulate the modulations of vortex shedding caused by an actively oscillating hydrofoil. By altering the vibration frequency and amplitude, the shedding frequency of vortices can be locked onto the structural vibration frequency. Another important discovery is that the dominant frequency of noise at the trailing edge of the actively vibrated hydrofoil has significantly shifted. Alongside the shift, there is a marked reduction in noise amplitude, denoting a dual acoustical modulation stemming from the vibratory intervention. These advancements provide pivotal contributions to the understanding of fluid-structure interactions and their resultant acoustic phenomena.