Experimental analysis of hydrofoil hydroelastic trailing edge vibrations

Abstract

This paper explores the conditions for hydro-elastic trailing edge vibrations on a NACA0015 aluminium hydrofoil clamped in a hydrodynamic tunnel. Test were performed for Reynolds numbers ranging from 2×10⁵ up to 9×10⁵ and various angle of attack, from 0 up to 10°. Laser vibrometry was used in order to describe the hydrofoil vibratory response. Time Resolved Particle Image Velocimetry (TR-PIV) was also used to visualise the flow and question the origin of the hydrodynamics excitation mechanism. This work aims to describe the different configurations generating strong coupling between the flow and a trailing edge structural eigenmode. It has been shown that vibrations of significant amplitude can be observed for a specific range of angle of attack from 3.5° to 8.5° and that the pressure surface boundary layer separation close to the trailing edge plays a key role in the hydrodynamics excitation mechanism.