Vortex-Shedding and the Maintenance of Thick Turbulent Boundary Layers on Long Cylinders in Axial Flow

Abstract

It has been found that vortices with cellular structure can be shed, over a range of Reynolds numbers, from circular cylinders in near-axial flow, even at yaw angles as small as 1°. Experimental data for shedding frequencies and vortex orientation are presented. It is suggested that piece-wise vortex shedding, resulting from cross-flows within the turbulent boundary layer, may play a crucial role in the mechanism of turbulence production necessary to sustain a very thick axisymmetric turbulent boundary layer.