MCDONNELL DOUGLAS ADVANCED ROTOR TEST PROGRAM
While the introduction of hingeless and bearingless rotors into the design of modern helicopters provides increased control moment and maneuverability, these rotors pose greater challenges to the dynamics and control systems engineers to accurately model the rotor system dynamics and predict their stability and loads characteristics. In an effort to obtain better predictive capabilities and to better understand bearingless rotor dynamics and loading, McDonnell Douglas Helicopter Systems (MDHS) and NASA Ames jointly conducted a wind tunnel test program to study the MDHS advanced bearingless rotor concept.
The test was conducted in the NASA Ames 40- by 80-Foot Wind Tunnel in 1992. The five-bladed, bearingless rotor was a pre-production version of the MD Explorer helicopter rotor system. The rotor was tested over a wide range of operating conditions including speeds of up to 200 kt (advance ratio = 0.49) and thrusts over 10,000 lb (1g = 5,800 lb). A significant amount of performance, loads, and stability data were acquired. In addition, the application of higher harmonic control (HHC) was seen to have significant effects on rotor vibration, loads, and noise levels.
Jacklin, S. A., Lau, B. H., Nguyen, K. Q., Smith, R. L., and McNulty, M. J., "Full-Scale Wind Tunnel Test of the McDonnell Douglas Five-Bladed Advanced Bearingless Rotor: Performance, Stability, Loads, Control Power, Vibration, and HHC Data," Proceedings of the American Helicopter Society Aeromechanics Specialist Conference, San Francisco, CA, January 1994. Paper No. 4.3.
McNulty, M., Jacklin, S., and Lau, B., "A Full-Scale Test of the McDonnell Douglas Advanced Bearingless Rotor in the NASA Ames 40- by 80-Ft Wind Tunnel," Proceedings of the 49th Annual National Forum American Helicopter Society, May 1993.
Nguyen, K., McNulty, M., Anand, V., and Lauzon, D., "Aeroelastic Stability of the McDonnell Douglas Advanced Bearingless Rotor," Proceedings of the 49th Annual National Forum American Helicopter Society, May 1993.
Point of Contact:
NASA Ames Research Center
Moffett Field CA 94035-1000