移動波状壁面上を飛ぶ2次元薄翼の空力特性

抄録

This paper investigates the aerodynamic response of a thin airfoil flying over and in proximity to a wavy wall surface which moves in the same direction as free stream but with a different velocity. Integral equation method relating the pressure on boundaries to downwash velocity is adopted for formulation, based on inviscid and small perturbation flow. Supposing the wall to be sinusoidal and the airfoil to be a flat plate at zero incidence, numerical calculations are made with a set of important parameters as airfoil height from the wall, wave length of wall surface, and the wall velocity. The influence of such parameters on the aerodynamic coefficients is divided into two parts, “First-order Ground Effect” and “Second-order Ground Effect” The latter is discussed in detail through the solution of Kemp-type gust. Numerical results show that the wave length and the traveling velocity of wall within a certain range have a great influence on the “Second-order Ground Effect”, with proximity to the ground.