MEASUREMENT OF AERODYNAMIC CHARACTERISTICS OF A HANG-GLIDER-WING BY GROUND RUN TESTS USING A TEST VEHICLE

In order to investigate longitudinal force and moment characteristics of a hang-glider-wing, ground run tests were conducted using a test vehicle. A hang-glider-wing was installed on a test vehicle using a six-components-balance for wind tunnel use. Aerodynamic force and moment were measrued during the vehicle run at various constant speeds. Geometrical twist distribution along the wing span was recorded as well. Measured force and moment data were corrected for possible ground effect and upwash effect due to movement of the vehicle. The lift curve slope was about 23％ smaller than that predicted by theory for a rigid wing of the same geometry. An abrupt increase in the pitching moment was measured as CL decreased from positive to negative. These particular features indicate that aeroelastic deformations affect the aerodynamic characteristics of hang-gliders and/or motor-hang-gliders are mandatory for their flight safety. Using the Moriya method, aeroelastic camber variations at typical spanwise stations were estimated for each combination of dynamic pressure and section angle of attack. Applying the Weissinger method, lift and pitching moment characteristics were analyzed twist distributions. By comparing these analyses with the measured data, geometrical deformations of the flexible wing were elucidated.