Unsteady aerodynamics of a wing-in-ground-effect airfoil flying over a wavy wall

Aerodynamic characteristics of an airfoil, the NACA 6409, dying over a wavy wall is investigated numerically. An Euler code based on the LU-factored a lgorithm and higher-order upwind scheme is constructed and its accuracy is tested with three benchmark problems: a NACA 4412 airfoil moving over a lev el ground, a NACA 0012 airfoil in free-Right pitching oscillation, and a NA CA 0012 airfoil flying over a wavy wall. The calculated Row about NACA 6409 airfoil over the wavy ground represented by a moving sine function indicat es that the aerodynamic property of the airfoil becomes sensitive if the wa ve number or amplitude of the wavy ground is increased and/or if the proxim ity of the airfoil to the ground is lowered.