Accession Number:

ADA165948

Title:

Hover and Forward Flight Acoustics and Performance of a Small-Scale Helicopter Rotor System.

Descriptive Note:

Technical memo.,

Corporate Author:

NATIONAL AERONUATICS AND SPACE ADMINISTRATION MOFFETT FIELD CA AMES RESEARCH CENTER

Personal Author(s):

Report Date:

1985-12-01

Pagination or Media Count:

31.0

Abstract:

A 2.1-m diam., 16-scale model helicopter main rotor was tested in hover in the test section of the NASA Ames 40- by 80-foot Wind Tunnel. Subsequently, it was tested in forward flight in the Ames 7- by 10-foot Wind Tunnel. The primary objective of the tests was to obtain performance and noise data on a small-scale rotor at various thrust coefficients, tip Mach numbers, and, in the latter case, various advance ratios, for comparison with similar existing data on full-scale helicopter rotors. This comparison yielded a preliminary evaluation of the scaling of helicopter rotor performance and acoustic radiation in hover and in forward flight. Correlation between model-scale and full-scale performance and acoustics was quite good in hover. In forward flight, however, there were significant differences in both performance and acoustic characteristics. A secondary objective was to contribute to a data base that will permit the estimation of facility effects on acoustic testing.

Subject Categories:

  • Helicopters
  • Acoustics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE