Correlation of Stability Test Results and Analysis for the 1/5 Scale V-22 Aeroelastic Model

A 1/5 scale semi-span aeroelastic model of the Joint Services Vertical Lift Aircraft (JVX), now designated the V-22, was tested in the NASA-Langley Transonic Dynamics Tunnel (TDT) during February-April and June-July 1984. The Froude-scaled model was initially configured in the V-22 Stage I preliminary design proposal configuration. During the course of the two wind tunnel entries a number of design parameters were varied, including the hub design, blade bending stiffness, wing spar stiffness, rotor pitch-flap coupling and pylon downstop configuration. The effect of compressibility was investigated by testing the model in both air and freon. Aeroelastic stability, loads and vibration data were obtained for a wide range of airspeeds, rotor speeds and conversion angles. The results were used to provide a data base for design of the V-22 aircraft. The data were correlated with aeroelastic stability analysis programs to validate the analytical tools being used in the full scale design process.