CALCULATION OF THE TURBULENT BOUNDARY LAYER WITH CONTINUOUSLY DISTRIBUTED SUCTION

A method for calculating the characteristic values of the turbulent boundary layer with suction is given. The method is based on an approximate solution of the momentum- and energy-integral equations of the boundary layer. It is applicable to arbitrary continuous distributions of both potential velocity and suction velocity. The assumptions for the shearing stress at the wall and the turbulen dissipation are taken from the theory of the turbulent boundary layer without suction in a slightly modified form by introducing a not yet specified function of the suction velocity. The calculation yields the momentum thickness and a shape factor which is regarded as a criterion for the position of the point of separation. Soutions in closed form are obtained for the flat plate at zero incidence with homogeneous suction and for boundary layer flows with similar velocity profiles (similar solutions). It is demonstrated by numerical examples that in order to avoid separation on the upper side of an aerofoil it is more economic to concentrate suction on a small region near the pressure minimum than to extend it over a larger area. (Author)
This Report is one in the Series 253-284 of papers presented at the Boundary Layer Research Meeting of the AGARD Fluid Dynamics Panel held from 25th to 29th April, 1960, in London, England.