Unsteady aerodynamic behavior and load characteristics of a VR-7 slat/
airfoil combination oscillating sinusoidally between 5-25 deg have bee
n studied. The unsteady, compressible Navier-Stokes equations are solv
ed on a multiblock grid using an approximate factorization finite diff
erence scheme. In the case of a single airfoil, a massive flow separat
ion and formation of a strong vortex is observed. The vortex-induced s
uction and the shedding of the vortex into the wake is responsible for
high aerodynamic loads and the subsequent stall of the airfoil. In th
e case of a slat/airfoil combination, the suction peak at the leading
edge of the airfoil is reduced significantly in comparison to the sing
le airfoil. Flow separation is confined to the trailing edge of the ma
in airfoil, and the formation of a strong vortical structure is not ob
served. The slat/airfoil combination does not experience a massive flo
w separation, and the aerodynamic lift does not undergo the characteri
stic deep dynamic stall hysteresis loops.