Mean flow characteristics of two-dimensional wings in ground effect

Abstract

The present study numerically investigates the aerodynamic characteristics of two-dimensional wings in the vicinity of the ground by solving two-dimensional steady incompressible Navier-Stokes equations with the turbulence closure model of the realizable k-ε model. Numerical simulations are performed at a various range of the normalized ground clearance by the chord length (0.1≤h/C≤1.25) for wide range of the angle of attack (0°≤α≤30°) in the pre-stall regime at one Reynolds number of 2×106 based on free stream velocity U∞ and the chord length. As the physical model of this study, a cambered airfoil of NACA 4406 has been selected by the performance test for various airfoils. The maximum lift-to-drag ratio is achieved at alpha;4°and h / C 0.1 Under the conditions of α4° and h / C 0.1 the effect of the Reynolds number on the aerodynamic characteristics of NACA 4406 is investigated in the range of 2× 105≤ Re≤ 2× 109. As Re increases, lC and dC augments and decreases, respectively, and the lift-todrag ratio increases linearly. ©SNAK, 2012.