Effects of Streamwise Vortices on Laminar Boundary-Layer Flow

Abstract

The effects of periodic transverse velocity fluctuations are investigated for boundary-layer flow over a flat plate. The method used is a perturbation expansion of the three-dimensional boundary-layer equations in terms of the small transverse velocity component. The equations are reduced to similarity form by means of suitable transformations. The second-order terms are expressed in terms of the first-order (Blasius) variables and are found to increase linearly with the streamwise coordinate. The present heat-transfer solution agrees with the more qualitative results of Persen. The derived velocity profiles are in exact agreement with the results of Crow’s more elaborate analysis based on the Navier-Stokes equations.