The Laminar Boundary Layer on a Rotating Circular Arc Blade

Abstract

The primary objective was to develop an exact solution to the simplest possible laminar boundary-layer problem for a curved rotating blade. It was formulated initially so that the results might be used to illuminate some of the characteristics of boundary-layer behavior on centrifugal impeller blades. The solution was obtained by a perturbation technique and the results compared to existing approximate solutions and related exact solutions. A primary result shows that rotation itself may induce laminar boundary-layer separation on a blade trailing face in the absence of free-stream, longitudinal adverse pressure gradients. This result is then interpreted to show that such a separation may become important for impellers of low ReD = ût D/ν; i.e., when ReD ≤ 900.