An Experimental Investigation of the Skewed Boundary Layer on a Rotating Body (2nd Report)

Abstract

Experiments were carried out on velocity distributions of the three-dimensional boundary layer on a cylindrical half body with a hemispherical nose rotating in axial stream. When the body remaind stationary, there was a separation bubble just behind the hemisperical nose. This separation bubble disappeared when the ratio of peripheral velocity of the cylinder to the reference main stream increased up to about 0.44, because of the additional acceleration produced by centrifugal force at the nose. This had also an effect on the polar plots of laminar boundary layer to modify the velocity profiles in the meridian direction. Momentum thicknesses obtained from the experiment agreed well with results of two theories. As in case of two-dimensional flow, boundary layer separation occurs far up-stream from the point which is predicted by the theory of the 4-th order polynominal velocity profiles.