DIVERGENT-TRAILING-EDGE AIRFOIL FLOW

The influence of recirculating flow on drag reduction associated with a divergent-trailing-edge (DTE) airfoil is provided by comparing the f low structure around a supercritical airfoil with a blunt trailing edg e to that around the same airfoil after DTE modification, Flow charact eristics are obtained by solution of compressible, Reynolds-averaged, Navier-Stokes equations with a linearized block implicit solution proc edure and mixing-length turbulence model, Results show that DTE modifi cation effects an increase in the streamwise length of the recirculati on region downstream of a blunt trailing edge that acts like a chordwi se extension to increase circulation, The divergent trailing edge give s the same lift at lower incidence and drag, so that lift-to-drag rati o is increased in transonic cruise, Drag creep is reduced by DTE modif ication because shock-induced drag is decreased as a result of a longe r recirculation region in the wake and its associated relocation and w eakening of the shock, which is greater than the increase in base drag .