Dynamic Characteristics of Rolling Delta Wing with High Angle of Attack under the Ground Effect

Dynamic properties of aerodynamic forces and moments acting on a delta wing were experimentally studied in a low-speed wind tunnel. The wing could make a smooth and periodic arbitrary motion, such as pitching, yawing, rolling, translation motions, and their combinations by a manipulator equipped with stepping motors controlled by a microcomputer, which had six degrees of freedom. The objective of the research is to analyze unsteady aerodynamics of the rolling delta wing with regard to the altitude from the ground. It was found that the hysteresis loops of lift, drag and rolling moment were drawn with the roll angles and amplified owing to the ground effect. The factors to determine the wing properties in the large angle of attack are the pressure on the windward side of the delta wing and the leading edge vortices which were broken down and reconstructed according to the wing motion. The pressure on the lower wing surface was also influenced by the clearance between the delta wing and the ground plate, which deduces the ventulli or stagnant effects.