An experiment of cavitating flow around a finite span hydrofoil

Abstract

This paper describes the experimental results of a finite span hydrofoil of NACA0012 section with elliptic planform (aspect ratio of 3).Lift and drag coefficients were measured at two angles of attack (α=10 and 20 deg.), where the cavitation number was changed from non-cavitating condition to super-cavitating condition.The pressure distribution of the hydrofoil and the wake distribution were measured at some typical cases. With this experiment the following results are obtained : (1) As the cavity grows, the ratio of cavity length to chord length becomes larger near the tip.(2) Under the non-cavitating condition or the condition of tip vortex cavitation there is a velocity acceleration near the tip-vortex. This acceleration changes to deceleration after inception of sheet type cavitation.