Effect of Wake Structure on Blade-Vortex Interaction Phenomena: Acoustic Prediction and Validation,

Abstract

During the Higher Harmonic Control Aeroacoustic Rotor Test, extensive measurements of the rotor aerodynamics, the far-field acoustics, the wake geometry and the blade motion for powered, descent, flight conditions were made. These measurements have been used to validate and improve the prediction of blade-vortex interaction (BVI) noise. The improvements made to the BVI modeling after the evaluation of the test data are discussed. The effects of these improvements on the acoustic-pressure predictions are shown. These improvements include re-structuring the wake, modifying the core size, incorporating the measured blade motion into the calculations and attempting to improve the dynamic blade response. A comparison of four different implementations of the Ffowcs Williams and Hawkings equation is presented. A common set of aerodynamic input has been used for this comparison. (AN)

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1995
Accession Number
ADA294477

Entities

People

  • Chee Tung
  • Heino Buchholz
  • Judith M. Gallman
  • Klaus J. Schultz
  • Wolf Splettstoesser

Organizations

  • National Aeronautics and Space Administration

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Acoustics
  • Aeroacoustics
  • Aerodynamics
  • Computer Programs
  • Experimental Data
  • Far Field
  • Fluid Dynamics
  • Frequency
  • Helicopter Rotors
  • Helicopters
  • Low Noise
  • Measurement
  • Pressure Distribution
  • Rotary Wing Aircraft
  • Strain Gages
  • United States
  • Waveforms

Fields of Study

  • Physics

Readers

  • Aerodynamics.
  • Computational Modeling and Simulation