Full Scale Tilt Rotor Hover Performance

The hover performance of three full-scale rotors was measured at the Ames Outdoor Aerodynamic Research Facility. The rotors, all designed for tilt-rotor aircraft, were the original metal blades for the XV-15 Tilt Rotor Research Aircraft, a set of composite, advanced technology blades for the XV-15, and a 0.658-scale model of the proposed V-22A Osprey (JVX) rotor. The composite advanced technology blades for the XV-15 were tested with several alternate blade root and blade tip configurations. This paper presents the performance of these three rotors; shows the effects of configuration changes and variations in the tip Mach number on rotor performance; and presents data on rotor wake velocity distributions, tip vortex geometry, and overall sound pressure levels. Measured rotor performance is compared with theoretical predictions, and the discrepancies are discussed.