Effects of Coriolis and Centrifugal Forces on Secondary Flows in Turbulent Boundary Layer.

Abstract

In order to clarify the turbulence behavior in impeller channels of turbomachinery, effects of the Coriolis and centrifugal forces on the turbulent boundary layer on the concave and convex surfaces were studied experimentally, using a rotating channel of rectangular cross section whose aspect ratio was 2 : 1. Velocity profiles and turbulence intensities were also compared with those for a channel having an aspect ratio of 4 : 1. In the present rotating channel it was found that secondary flows generated by the centrifugal and Coriolis forces have a large effect on the time-averaged and turbulence components in the boundary layer along the concave and convex surfaces, and that the suppression of turbulence expected on the lower-pressure side of a two-dimensional flow is not observed because of the accmulation of lower energy fluids and the interference of the fluids with the primary flow.