Reynolds-averaged Navier-Stokes computations of a flap-side-edge flowfield

An extensive computational investigation of a generic high-lift configurati on comprising a wing and a half-span flap reveals details of the mean flowf ield for flap deflections of 29 and 39 deg. The computational effort involv es solutions of the thin-layer form of the Reynolds-averaged Navier-Stokes equations. For bath Rap deflections, the steady results show the presence o f a dual-vortex system: a strong vortex forming on the lower portion of the flap side edge and a weaker one forming near the edge on the flap top surf ace. Downstream, the vortex on the flap side edge grows and eventually merg es with the vortex on the flap top surface. Comparison of on- and off-surfa ce BOK quantities with our previous experimental measurements shows remarka ble agreement, For the 39-deg gap deflection, the calculation also reveals the occurrence of a vortex breakdown, which is corroborated bg five-hole pr obe velocity measurements performed in the Quiet Flow Facility at NASA Lang ley Research Center, The presence of the vortex breakdown significantly alt ers the flowfield near the side edge.