The computation of separated diffuser flows

A summary of recent research into internal flows with separation is presented. Cases include incompressible, straight-walled channels with both laminar and turbulent boundary layers for plenum exit conditions. Fully developed separations were studied for both two dimensional and axisymmetric flows. Successful computer programs for predicting such flows were constructed. A more advanced program was created that successfully predicts first-order flow quantities in channels with incipient and small amounts of separation. Emphasis is placed on why many earlier attempts to model separated flows have failed and how the difficulties can be corrected by appropriate modeling of the interaction between the pressure field of the outer flow and the blockage effects of boundary layers and separated zones.