Numerical investigation of slat and compressibility effects for a high-lift wing

Three-dimensional multielement wings are simulated to investigate slat aerodynamics, numerical modeling techniques, and compressibility effects for high-lift flows. The computations are performed by solving both the incompressible and compressible Navier-Stokes equations on structured, overset grids. Turbulence is modeled via the one-equation Spalart-Allmaras model. All of the computed cases include the main wing with a half-span flap deflected to 40 deg. Three leading-edge configurations of this unswept wing are then considered: no slat, full-span slat, and. a threle-quarter-span slat. The slat elements are deployed to 6 deg. Computations of the model, which simulates a landing configuration at 10-deg angle of attack and a chord-based Reynolds number of 3.7 X 106, are validated with surface pressure measurements acquired at the NASA Ames 7- by 10-Foot Wind Tunnel. By the observation of the changes to the high-lift flowfield by adding the slat, as well as by varying its spanwise length, a detailed computational assessment of a properly, configured slat is achieved. Moreover, the results increase the computational knowledge of how to model the slat flow physics accurately. For the three-element wing with partspan slat, modeling compressibility can have a large impact on the flowfield solution. Overall, compressibility is small, but it has significant global effects on the circulation and flow separation of each element.