Leading Edge Flutter of a Supercavitating Hydrofoil

Citation

Oey, Nicolaus Kiam Thian (1979) Leading Edge Flutter of a Supercavitating Hydrofoil. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/9DGB-DW93. https://resolver.caltech.edu/CaltechETD:etd-11032006-091936

Abstract

Leading edge flutter is a problem that is unique to a super-cavitating hydrofoil. At high speed, the leading edge portion has been observed to oscillate while the trailing edge remains motionless.

In this study, several flat plate hydrofoils were tested. The experimental results indicate that the phenomenon is a complex function of speed, angle of attack, cavitation number and mass ratio. Leading edge flutter was also observed to cause cavity pinching. A theoretical study was also conducted. Two mathematical models are presented here. The first one models the flexible chord foil as a rigid chord foil hinged at the trailing edge; the second model treats the fluid-structure interaction problem of a flexible chord foil cantilevered at the trailing edge. Both models resemble leading edge flutter near zero cavitation number in some respects. At short and moderate cavity lengths, leading edge flutter phenomenon is influenced by the cavity closure condition.

Thesis Files