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

Abstract

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)

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Document Details

Document Type
Technical Report
Publication Date
Aug 01, 1983
Accession Number
ADA134612

Entities

People

  • M-nabil H. Hamouda
  • Wayne R. Mantay
  • William T. Yeager Jr.

Organizations

  • National Aeronautics and Space Administration

Tags

DTIC Thesaurus Topics

  • Actuators
  • Aerodynamic Configurations
  • Aeronautics
  • Aircrafts
  • Airframes
  • Differential Equations
  • Equations
  • Frequency
  • Fuselages
  • Helicopters
  • Linear Differential Equations
  • Models
  • Resonance
  • Resonant Frequency
  • Spars
  • Wind Tunnel Tests
  • Wind Tunnels

Fields of Study

  • Physics

Readers

  • Aerodynamics.
  • Aerospace Engineering