EROSION AND NOISE ATTENUATION TESTS ON A 50 FT. CHALK TUNNEL USED AS A JET ENGINE NOISE MUFFLER

Abstract

Tests were made on a small earth tunnel to check its resistance to erosion and to assess the noise reduction that may be expected when such a device is used to muffle the exhaust noise of a jet aircraft. Photographs taken before and after tests with a Hunter aircraft are given, and estimates made of the attenuations due to absorption of sound by the chalk walls, a 30 degree bend, and an exit which directs the efflux up into the air. It is concluded that there will be no serious erosion problems in a chalk tunnel if the gas velocity is less than 800 ft/sec. and that the 50 ft. tunnel gave a maximum of 22 dB attenuation.

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Document Details

Document Type
Technical Report
Publication Date
Nov 03, 1964
Accession Number
AD0464435

Entities

People

  • M. A. Beeny

Tags

DTIC Thesaurus Topics

  • Absorption
  • Aircrafts
  • Attenuation
  • Engine Noise
  • Engines
  • Exhaust Gases
  • Exhaust Systems
  • Gases
  • Ground Level
  • Jet Aircraft
  • Jet Engine Noise
  • Jet Engines
  • Loudspeakers
  • Measurement
  • Mufflers
  • Noise
  • Sound Pressure

Fields of Study

  • Physics

Readers

  • Acoustical Oceanography.
  • Geotechnical Engineering.
  • Internal Combustion Engine (ICE) Technology.