Abstract
Results of the measurement of flow properties in the boundary layer on a cylinder with and without spin in an axial flow in the presence of a single protrusion are presented. A wedge-shaped region of turbulent flow originates at the protrusion and extends downstream. The profiles of the axial and peripheral components of the mean velocity on the stationary cylinder show the existence of a horseshoe·shaped vortex. The velocity fluctuations take their peak values on either side of the region of turbulence wedge close to the wall. Hot-wire data with a rotating cylinder are digitized and made into an ensemble average. The ensemble-averaged velocities and rms fluctuations also show the existence of a set of streamwise vortices. The mean velocity vector in the x-y plane varies greatly between the outside and the inside of the turbulence wedge as well as across the wedge region. The character of the evolution of the turbulence wedge is also presented.
