Laminar Boundary Layer on a Rotating Thin Cylinder in an Axial Flow : Effect of Self-Induced Pressure Gradient on Separation

Abstract

For a prescribed external pressure gradient, the laminar boundary layer equations which govern the flow developing on a rotating thin circular cylinder in an axial flow are solved numerically. It is shown that both self-induced favorable pressure gradient caused by rotation and adverse pressure gradient largely influence the flow fields. Although the two-dimensional boundary layer equations usually have a singularity at the separation point, in this paper the numerical solutions are obtained to integrate the equations without using special techniques through the separation point and into the region of reverse flow. Alternatively the numerical instability and the abrupt change of the slope of stream lines appear downstream beyond separation point and computation is terminated. It is suggested that the singular properties occur not on the wall but within the boundary layer.