INVESTIGATION OF WING SHIELDING EFFECTS ON CTOL ENGINE NOISE

A full scale engine wing shielding investigation was conducted at the Lewis Research Center using a 97,900-N (22,000 lb) thrust turbofan engine and a simulated wing section sized around a conventional-take-off type four-engine narrow body airplane. Sound data were obtained for the wing placed at seven positions in a plane parallel to the engine axis, and were compared to data obtained without the wing at both take off and approach power. In addition, the engine was operated with and without extensive acoustic treatment, including a sonic inlet in order to evaluate wing shielding effectiveness with a highly suppressed engine. The wing shielding effectiveness was also calibrated using a 3.8 cm diam air nozzle as a second source. Results indicated that even though about 10 dB broad band shielding was achieved, the equivalent flyover noise reduction was less than 3.0 EPNdB for most configurations.

  • Supplemental Notes:
    • Presented at the 5th Annual Aeroacoustics Conference, Seattle, 12-14 March 1979, Sponsored by AIAA.
  • Corporate Authors:

    Department of the Navy

    The Pentagon
    Washington, DC  United States  20350
  • Authors:
    • Bloomer, H E
  • Publication Date: 1979

Media Info

  • Pagination: 34 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00197942
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: NASA-TM-79078
  • Files: TRIS
  • Created Date: Sep 15 1980 12:00AM