An Experimental Investigation Of The Aeromechanical Stability Of A Hingeless Rotor In Hover And Forward Flight PDF Download

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An Experimental Investigation of the Aeromechanical Stability of a Hingeless Rotor in Hover and Forward Flight

An Experimental Investigation of the Aeromechanical Stability of a Hingeless Rotor in Hover and Forward Flight
Author:
Publisher:
Total Pages: 24
Release: 1987
Genre:
ISBN:

Download An Experimental Investigation of the Aeromechanical Stability of a Hingeless Rotor in Hover and Forward Flight Book in PDF, ePub and Kindle

Analysis and testing were conducted in the Langley Transonic Dynamics Tunnel to investigate the aeromechanical stability of a soft inplane hingeless rotor model. Rotor stability data were obtained in hover and in forward flight up to an advanced ratio of 0.35. Model rotor parameters evaluated were blade sweep and droop, pre-cone of the blade feathering axis, and blade pitch-flap coupling. Data obtained during these tests are presented without analysis. Keywords: Hovering; Hingeless helicopter rotor dynamics; Helicopter rotor blades; Ground resonance.


Aeromechanical Stability of a Hingeless Rotor in Hover and Forward Flight: Analysis and Wind Tunnel Tests

Aeromechanical Stability of a Hingeless Rotor in Hover and Forward Flight: Analysis and Wind Tunnel Tests
Author:
Publisher:
Total Pages: 24
Release: 1983
Genre:
ISBN:

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A research effort of analysis and testing has been conducted in the NASA-Langley Transonic Dynamics Tunnel to investigate the ground resonance phenomenon of a soft in-plane hingeless rotor. Experimental data were obtained using a 9 ft. (2.74 m) diameter model rotor in hover and forward flight. Eight model rotor configurations were investigated. Configuration parameters included pitch-flap coupling, blade sweep and droop, and precone of the blade feathering axis. An analysis based on a comprehensive analytical model of rotorcraft aerodynamics and dynamics was used for this study. The moving-block method was used to experimentally determine the regressing lead-lag mode damping. Good agreement has been obtained between the analysis and test. Both analysis and experiment indicated ground resonance instability in hover. The paper presents an outline of the analysis, a description of the experimental model and procedures, and comparison of the analytical and experimental data. (Author).


Aeromechanical Stability of a Hingeless Rotor in Hover and Forward Flight

Aeromechanical Stability of a Hingeless Rotor in Hover and Forward Flight
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
Total Pages: 24
Release: 2018-07-21
Genre:
ISBN: 9781723442025

Download Aeromechanical Stability of a Hingeless Rotor in Hover and Forward Flight Book in PDF, ePub and Kindle

A research effort of analysis and testing was conducted to investigate the ground resonance phenomenon of a soft in-plane hingeless rotor. Experimental data were obtained using a 9 ft. (2.74 m) diameter model rotor in hover and forward flight. Eight model rotor configurations were investigated. Configuration parameters included pitch flap coupling, blade sweep and droop, and precone of the blade feathering axis. An analysis based on a comprehensive analytical model of rotorcraft aerodynamics and dynamics was used. The moving block was used to experimentally determine the regressing lead lag mode damping. Good agreement was obtained between the analysis and test. Both analysis and experiment indicated ground resonance instability in hover. An outline of the analysis, a description of the experimental model and procedures, and comparison of the analytical and experimental data are presented. Yeager, W. T., Jr. and Hamouda, M. N. H. and Mantay, W. R. Langley Research Center NASA-TM-85683, NAS 1.15:85683, AVRADCOM-TR-83-B-5, AD-A134612 DA PROJ. 1L2-62209-AH-76; RTOP 505-42-23-05


Aeromechanical Stability of a Hingeless Rotor in Hover and Forward Flight

Aeromechanical Stability of a Hingeless Rotor in Hover and Forward Flight
Author: William T. Yeager
Publisher:
Total Pages: 19
Release: 1983
Genre:
ISBN:

Download Aeromechanical Stability of a Hingeless Rotor in Hover and Forward Flight Book in PDF, ePub and Kindle

A research effort of analysis and testing has been conducted in the NASA-Langley Transonic Dynamics Tunnel to investigate the ground resonance phenomenon of a soft in-plane hingeless rotor. Experimental data were obtained using a 9 ft. (2.74 m) diameter model rotor in hover and forward flight. Eight model rotor configurations were investigated. Configuration parameters included pitch-flap coupling, blade sweep and droop, and precone of the blade feathering axis. An analysis based on a comprehensive analytical model of rotorcraft aerodynamics and dynamics was used for this study. The moving-block method was used to experimentally determine the regressing lead-lag mode damping. Good agreement has been obtained between the analysis and test. Both analysis and experiment indicated ground resonance instability in hover. The paper presents an outline of the analysis, a description of the experimental model and procedures, and comparison of the analytical and experimental data. (Author).