The Effect of Flight on the Noise of Subsonic Jets,

Abstract

The noise of a single-stream circular jet and a coaxial jet with coplanar nozzles of 2.5 area ratio has been measured under simulated flight conditions. The majority of tests were conducted with the single-stream jet and primary section of the coaxial jet at a nominal temperature of 880 K. The data have been used to quantify the effect of jet temperature and were combined with measurements from an earlier test series to establish a prediction method for the effect of flight on the noise of single-stream subsonic jets. This method is based on jet noise theory modified by experimentally derived constants. For coaxial jets it is concluded that the noise reductions, which are independent of the secondary stream velocity, are predicted to an acceptable degree by the method suggested for unheated single-stream jets.

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Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1976
Accession Number
ADA041730

Entities

People

  • B. J. Cocking

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Acoustics
  • Acquisition
  • Aircrafts
  • Boundary Layer
  • Data Acquisition
  • Diameters
  • Distortion
  • Doppler Effect
  • Frequency
  • Mach Number
  • Measurement
  • Microphones
  • Noise
  • Noise Reduction
  • Nozzle Area Ratio
  • Secondary Flow
  • Sound Pressure

Fields of Study

  • Physics

Readers

  • Acoustics.
  • Combustion and Flow Dynamics.