WIND TUNNEL MODELING OF ROTOR VIBRATORY LOADS

A tandem rotor dynamic model has been designed, manufactured and tested at the Boeing Vertol 20 × 20 ft. V/STOL Wind Tunnel. The model measures vibratory hub loads with five independent measuring systems on each rotor. This four-bladed model was flown at full scale tip speeds through a wide envelope of airspeeds and thrusts, achieving a maximum speed of 200 knots. The various measurement systems are discussed, calibration activities are reviewed and test results are presented.