Accession Number:

ADA123499

Title:

Reduction of High-Speed Impulsive Noise by Blade Planform Modification of a Model Helicopter Rotor.

Descriptive Note:

Technical memo.,

Corporate Author:

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION HAMPTON VA LANGLEY RESEARCH CENTER

Personal Author(s):

Report Date:

1982-12-01

Pagination or Media Count:

62.0

Abstract:

An experiment has been performed to investigate the reduction of high-speed impulsive noise for the UH-1H helicopter by using an advanced main rotor system. The advanced rotor system had a tapered blade planform compared with the rectangular planform of the standard rotor system. Models of both the advanced main rotor system and the UH-1H standard main rotor system were tested at 14 scale in the Langley 4- by 7-Meter Tunnel. In-plane acoustic measurements of the high-speed impulsive noise demonstrated that the advanced rotor system on the UH-1H helicopter reduced the high-speed impulsive noise by up to 20 dB, with a reduction in overall sound pressure level of up to 6 dB. Author

Subject Categories:

  • Helicopters
  • Transport Aircraft
  • Acoustics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE