Flow Environment Study Near The Empennage Of A 15 Scale Helicopter Model

Author : National Aeronautics and Space Adm Nasa
Publisher : Independently Published
ISBN 13 : 9781723726729
Total Pages : 32 pages
Book Rating : 4.7/5 (267 download)

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Download or read book Flow Environment Study Near the Empennage of a 15-Percent Scale Helicopter Model written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-09-15 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Development of advanced rotorcraft configurations has highlighted a need for high-quality experimental data to support the development of flexible and accurate analytical design tools. To provide this type of data, a test program was conducted in the Langley 14- by 22-Foot Subsonic Tunnel to measure the flow near the empennage of a 15-percent scale powered helicopter model with an operating tail fan. Three-component velocity profiles were measured with laser velocimetry (LV) one chord forward of the horizontal tail for four advance ratios to evaluate the effect of the rotor wake impingement on the horizontal tail angle of attack. These velocity data indicate the horizontal tail can experience unsteady angle of attack variations of over 30 degrees due to the rotor wake influence. The horizontal tail is most affected by the rotor wake above advance ratios of 0.10. Velocity measurements of the flow on the inlet side of the tail fan were made for a low-speed flight condition using conventional LV techniques. The velocity data show an accelerated flow near the tail fan duct, and vorticity calculations track the passage of main rotor wake vortices through the measurement plane.Gorton, Susan Althoff and Berry, John D. and Hodges, W. Todd and Reis, Deane G.Langley Research CenterHELICOPTERS; DESIGN ANALYSIS; HORIZONTAL TAIL SURFACES; ROTARY WING AIRCRAFT; SCALE MODELS; ANGLE OF ATTACK; VORTICITY; WAKES; VELOCITY MEASUREMENT; VELOCITY DISTRIBUTION