EXPERIMENTAL-STUDY OF ROTOR BODY AERODYNAMIC INTERACTIONS

Results are presented that quantify the mutual interactional aerodynamic effects between an articulated rotor and a fuselage consisting of a body of revolution. Wind-tunnel tests were conducted on the isolated body, the isolated rotor, and the rotor/body combination from hover up to an advance ratio of 0.25. Forces and moments on the body and rotor were measured by independent strain-gauge balances. In addition, measurements of both the mean and unsteady pressures on the body were acquired. The results have shown that relatively large forces and pitching moments are created on the body by the presence of the rotor. These loads were significantly affected by variations in both rotor thrust and advance ratio. In turn, the presence of the body produces a moderate increase in rotor thrust and a reduction in power required relative to the isolated rotor performance. Unsteady pressure fluctuations on the body were extremely significant and generally exceeded the mean pressure values. These unsteady pressures were present over the full range of test conditions and appeared to arise from periodic passage of the rotor blades, coupled with either close interactions or direct impingement of discrete wake vortices with the body. © 1989 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.