Flap Lag Stability Data For A Small Scale Isolated Hingeless Rotor In Forward Flight

Author : National Aeronautics and Space Administration (NASA)
Publisher : Createspace Independent Publishing Platform
ISBN 13 : 9781723057533
Total Pages : 118 pages
Book Rating : 4.0/5 (575 download)

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Download or read book Flap-Lag Stability Data for a Small-Scale Isolated Hingeless Rotor in Forward Flight written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-17 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: An isolated, hingeless rotor with discrete flap and lead-lag flexures and relatively rigid blades was tested in the Aeroflightdynamics Directorate's 7- by 10-Foot Wind Tunnel. The lead-lag stability of a structurally simple rotor configuration in forward flight was determined. The model tested had no cyclic pitch control, and was therefore operated untrimmed at several collective pitch angles, at shaft angles from 0 deg to -20 deg, and at advance ratios as high as 0.55. Two inplane natural frequencies, 0.61/rev and 0.72/rev, were tested for configuration both with and without structural flap lag coupling. Concomitant hover testing of the model was also conducted. Representative plots of the frequency and damping data are presented to show general trends, and complete tabular data and model properties information are included for use in detailed correlation exercises. The most prominent feature of the forward flight data is an abrupt increase in damping with advance ratio at certain high-speed, high shaft-angle conditions, with high flapping loads. The hover data are consistent with previous experimental and theoretical results for hingeless rotors without kinematic couplings. Overall, the data quality is very good and the data are expected to be useful in the development and validation of rotor aeroelastic stability analyses. Mcnulty, Michael J. Ames Research Center AEROELASTICITY; DAMPING; DYNAMIC STABILITY; HORIZONTAL FLIGHT; HOVERING; RIGID ROTORS; ROTARY WINGS; ROTOR DYNAMICS; FLEXING; INERTIA; PITCH (INCLINATION); RESONANCE TESTING; RESONANT FREQUENCIES; ROTOR SPEED; STIFFNESS...