A Study on Fluid-Structure Interaction Performance of a Flexible Hydrofoil

Abstract

To research the flexible hydrofoils’ hydroelastic response, the fluid-structure interaction (FSI) characteristic investigation is conducted on the basis of the analysis of a rigid hydrofoil’s hydrodynamic performance. For a rigid cantilevered rectangular hydrofoil, the pitching hydrodynamic performance is calculated using boundary motion with remeshing strategy. The Laminar Separation Bubble (LSB) and turbulent transition are captured. Numerical flow analysis revealed that the LSB occurs at 0.8c when pitching at initial angle of attack. As the angle increases to 5.1°, the laminar to turbulent transition occurs and the lift presents an inflection. For a geometric equivalent flexible hydrofoil, the static FSI characteristic is researched using oneway and two-way FSI method. The lift decreases and the drag increases using two-way compared to one-way FSI. The center of pressure and the maximum deformation move from trailing edge to leading edge as the angle of attack increases, showing the necessary of two-way FSI calculation. The transient FSI characteristic of the flexible hydrofoil is then studied using LES model. The lift fluctuation at 8° in frequency domain is calculated . The dry mode and wet mode natural frequency of the flexible hydrofoil are calculated to simulate the vibration performance, which meet the experiment data quite well, laying foundation for further research on the hydroelastic vibration response.