Rotating flying disks and formation of trailing vortices

Abstract

An experimental investigation on the flow past a flying disk is carried out in a low-speed wind tunnel. Using flow visualization techniques supplemented by Digital Particle Image Velocimetry (PIV), detailed flow characteristics depicting the trailing vortices, boundary layer separation and wake structure are obtained. Effects of disk rotation on the boundary layer transition and separation are studied. Results indicate that the effect of rotation on the vortex strength becomes negligible at high angles of attack. At low lifting conditions of the present configuration, the rotation suppresses the boundary layer separation near the trailing edge and increases the downwash. In the intermediate angles, however, the leading edge separation bubble is affected by the rotation. The flow transition over the advancing surface is also noted. General flow physics described herein is expected to hold for other similar configurations.