Visualization and PIV Study of Vortical Flows behind a Paraboloidal-Nose Cylinder with a Towing Model

Abstract

Visualization and PIV measurements were conducted in a towing air-chamber for wake vortices behind a paraboloidal-nose cylinder at high angles of attack. The evolution of the wake was then measured by a particle image velocimetry (PIV) using cross-sectional and longitudinal cuts which were produced by the sheet illumination of the Nd:YAG laser. To visualize the three-dimensional evolution of flow in the vicinity of wall, we employed a titanium tetrachloride (TiCl4). It was predicted by the PIV study that serial vortex loops with almost constant spacing appear around the main vortex.