THREE-DIMENSIONAL VORTEX DYNAMICS NEAR A WALL.

Abstract

The three-dimensional deformation of an artificially generated line vortex near a flat wall is examined by means of flow visualization and quantitative conditioned sampling of a hot-wire anemometer. The vortex is observed to undergo a very rapid deformation from the rectilinear form to a hairpinlike shape. Similar shapes have been observed in the case of driven flows in laminar boundary layers and during the transition to turbulent flow. In the present case the vortices are driven by a rotor configuration of larger scale than the boundary layer thickness. Refs.