Feasibility Analysis of Fixed Plates in Chord-Dominated Static Ground Effect Wind-Tunnel Experiment

Abstract

In ground effect wind-tunnel experiments, fixed plates are widely adopted to replace the moving ground, which will affect the reliability of experimental results. In this paper, a numerical investigation is conducted to study the feasibility of a fixed plate in the chord-dominated static ground effect experiment. The incompressible Reynolds-averaged Navier–Stokes equations and shear stress transport turbulence model are solved. The feasibility of a fixed plate is determined by the camber effect, the blocking effect, and the boundary-layer effect. The camber effect dominates the suction distribution on the airfoil upper surface, and the blocking and boundary-layer effects together govern the pressure distribution on the lower surface. With the decreasing plate length, the modeling ability of camber effect decreases slightly first and then sharply; and the modeling ability of the blocking effect gradually restores due to the gradually weakened boundary-layer effect. A fixed plate can reproduce the lift and pitching moment accurately due to the accurate duplication of pressure distribution, but it fails in drag due to the inaccurate modeling of shear stress distribution. The optimal fixed plate configurations for different angles of attack and ride heights are given for ground effect wind-tunnel experiments.