Portland, Oregon
June 12, 2005
June 12, 2005
June 15, 2005
2153-5965
9
10.1208.1 - 10.1208.9
10.18260/1-2--15111
https://peer.asee.org/15111
1243
Teaching Graduate Rotorcraft Design Based on Twenty Years of Experience
Dr. Daniel P. Schrage Professor and Director Center of Excellence in Rotorcraft Technology School of Aerospace Engineering Georgia Institute of Technology Atlanta, GA 30332-0150
Introduction Rotorcraft is a general term for rotary-wing aircraft and includes all aircraft that include any rotary-wing device for generating lift or propulsion for a portion of the aircraft’s flight envelope. Therefore, rotorcraft includes helicopters, autogyros, tilt-rotor aircraft, and compound helicopters (which include both wings and auxiliary propulsion devices). Rotorcraft are typically low disk loading vehicles operating below 50 lbs/ft2, where disk loading is defined as the ratio of the gross weight to rotor disk area. The author has personally been involved with rotorcraft, since learning to fly Army helicopters in the late 1960s which included a tour as an Army helicopter pilot and commander in combat in Southeast Asia. Involvement in rotorcraft design and development commenced with an assignment as an aeroelasticity and dynamics engineer with the U.S. Army Aviation Systems Command in 1974, following receiving a M.S. degree in Aerospace Engineering at Georgia Tech. Participation in the development and transition to production of today’s fleet of Army helicopters: the UH-60 Black Hawk, the AH-64 Apache, the CH-47 Chinook, and the OH-58D Kiowa Warrior, led to some unique insights and experience related to these complex and unique, but wonderful machines. Leading the development of the next generation of rotorcraft, the LHX-RAH-66 Comanche, in the early 1980s provided an understanding of the role of technology, as well as its fickleness. Teaching rotorcraft design at Georgia Tech since 1984 as the Rotorcraft Design Professor and leading the Center of Excellence in Rotorcraft Technology (CERT) as its Director since 1986 has led to an understanding and appreciation of the role of interdisciplinary basic research for the advancement of complex systems, such as rotorcraft. This paper will attempt to provide some lessons learned from twenty years experience in teaching rotorcraft design.
Understanding Rotorcraft Rotorcraft are extremely complex machines due to the interdisciplinary interactions that take place throughout their flight regimes. The helicopter schematic provided in Figure 1 provides some brief descriptions of some of the physical phenomena that rotorcraft encounter. The easiest way to explain this environment is to cite that in forward flight at a single cruise flight speed of approximately 140 knots the airspeed from the retreating blade tip to the advancing blade tip crosses the entire subsonic speed range from Mach number zero to almost one. This results in Dynamic Stall on the retreating blade to Transonic Flow (Shock Waves) on the advancing blade. In addition, the time varying aerodynamics at each section of the rotor blades and the limberness
Proceedings of the 2005 American Society for Engineering Education Annual Conference & Exposition Copyright © 2005, American Society for Engineering Education
Schrage, D. (2005, June), Teaching Graduate Rotorcraft Design Based On Twenty Years Of Experience Paper presented at 2005 Annual Conference, Portland, Oregon. 10.18260/1-2--15111
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