Full-Scale Investigation of Several Jet-Engine Noise-Reduction Nozzles Metadata

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  • Main Title Full-Scale Investigation of Several Jet-Engine Noise-Reduction Nozzles
  • Series Title NACA Technical Reports


  • Author: Coles, Willard D.
    Creator Type: Personal
  • Author: Callaghan, Edmund E.
    Creator Type: Personal


  • Originator: Lewis Flight Propulsion Laboratory
    Contributor Type: Organization
    Contributor Info: National Advisory Committee for Aeronautics. Lewis Flight Propulsion Lab


  • Creation: 1958-01-01


  • English


  • Content Description: A number of noise-suppression nozzles were tested on full-scale engines. In general, these nozzles achieved noise reduction by the mixing interference of adjacent jets, that is, by using multiple-slot-nozzles. Several of the nozzles achieved reductions in sound power of approximately 5 decibels (nearly 70 percent) with small thrust losses (approx. 1 percent). The maximum sound-pressure level was reduced by as much as 18 decibels in particular frequency bands. Some of the nozzles showed considerable spatial asymmetry; that is, the sound field was not rotationally symmetrical. A method of calculating the limiting frequency effected by such nozzles is presented. Furthermore data are shown that appear to indicate that further reductions in sound power will not be easily achieved from nozzles using mixing interference as a means of noise suppression.


  • Name: National Advisory Committee for Aeronautics Collection
    Code: NACA
  • Name: Technical Report Archive and Image Library
    Code: TRAIL


  • Name: UNT Libraries Government Documents Department
    Code: UNTGD


  • Rights Access: public
  • Rights License: pd
  • Rights Statement: No Copyright, Unclassified, Unlimited, Publicly available

Resource Type

  • Report


  • Text


  • Accession or Local Control No: 93R21656
  • URL: http://hdl.handle.net/2060/19930092366
  • Report No.: NACA-TR-1387
  • Center for AeroSpace Information Number: 19930092366
  • Archival Resource Key: ark:/67531/metadc60812