A Comparison of the Acoustic and Aerodynamic Measurements of a Model Rotor Tested in Two Anecholic Wind Tunnels

Abstract

Two aeroacoustic facilities--the CEPRA 19 in France and the DNW in the Netherlands--are compared. The two facilities have unique acoustic characterists that make them appropriate for acoustic testing of model-scale helicopter rotors. An identical pressure-instrumented model-scale rotor was tested in each facility and acoustic test results are compared with full-scale rotor test results. Blade surface pressures measured in both tunnels were used to correlate nominal rotor operating conditions in each tunnel, and also used to assess the steadiness of the rotor in each tunnel's flow. In-the-flow rotor acoustic signatures at moderate forward speeds (35-50 m/sec) are presented for each facility and discussed in relation to the differences in tunnel geometries and aeroacoustic characteristics. Keywords: Acoustics; Anechoic wind tunnels; Model helicopter rotors; Blade pressures.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1986
Accession Number
ADA175717

Entities

People

  • D. A. Boxwell
  • F. H. Schmitz
  • K. J. Schultz
  • S. Lewy
  • W. R. Splettstoesser

Organizations

  • National Aeronautics and Space Administration

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Acoustic Properties
  • Acoustic Signatures
  • Acoustics
  • Aerodynamic Characteristics
  • Airframes
  • Army Aviation
  • Boundary Layer
  • Fluid Dynamics
  • Geometry
  • Helicopter Rotors
  • Helicopters
  • Measurement
  • Pressure Measurement
  • Rotary Wing Aircraft
  • Secondary Flow
  • Turbulent Mixing
  • Wind Tunnels

Fields of Study

  • Physics

Readers

  • Acoustics.
  • Aerodynamics.