INTEGRAL METHOD FOR CALCULATING TURBULENT SKIN FRICTION IN TWO-DIMENSIONAL INCOMPRESSIBLE SEPARATED FLOWS.
An integral method is presented for computing incompressible two-dimensional turbulent skin friction for separated flows based on the inner-variable theory. Using a velocity profile in the form of the logarithmic law and wake, continuity and momentum equations are integrated across the boundary layer in terms of inner-variables u** plus and y** plus . With the aid of correlations relating the wake parameters to the pressure gradient parameter, derived from experimental results of several near-separating and separated flows, the governing equations are reduced to a single differential equation in skin friction. Predictions by the theory for several separated flows show satisfactory agreement with experimental data.