Accession Number:

ADA175717

Title:

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

Descriptive Note:

Technical memorandum rept.

Corporate Author:

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION MOFFETT FIELD CA AMES RESEARCH CENTER

Report Date:

1986-11-01

Pagination or Media Count:

56.0

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 tunnels flow. In-the-flow rotor acoustic signatures at moderate forward speeds 35-50 msec 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.

Subject Categories:

  • Test Facilities, Equipment and Methods
  • Acoustics
  • Jet and Gas Turbine Engines

Distribution Statement:

APPROVED FOR PUBLIC RELEASE