Study on Flow-induced Vibration Characteristics of 2-DOF Hydrofoil Based on Fluid-Structure Coupling Method

The flutter of a hydrofoil can cause structural damage and failure, which is a dangerous situation that must be avoided. In this work, based on computational fluid dynamics and structural finite element methods, a co-simulation framework for the flow-induced vibration of hydrofoil was established to realize fluid-structure interaction. Numerical simulation research was conducted on the flow-induced vibration characteristics of rigid hydrofoil with 2-DOF under uniform flow, and the heave and pitch vibration responses of hydrofoil were simulated. The purpose is to capture the instability of hydrofoil vibration and evaluate the influence of natural frequency ratio and inertia radius on vibration state to avoid the generation of flutter. The results indicate that when the inflow velocity increases to a certain critical value, the hydrofoil will enter the flutter critical state without amplitude attenuation. The attack angle of a hydrofoil has a significant impact on the vibration amplitude of heave and pitch. Additionally, the natural frequency ratio and inertia radius of the hydrofoil significantly affect the critical velocity of the flutter. Adjusting the natural frequency ratio by reducing the vertical stiffness or increasing the pitch stiffness can move the vibration from a critical state to a convergent state.