Accession Number : ADA293277

Title :   An Active Liner System for Jet Engine Exhaust Silencers. Phase 1.

Descriptive Note : Final rept. 1 Jul 93-30 Jun 94,

Corporate Author : BBN SYSTEMS AND TECHNOLOGIES CORP CAMBRIDGE MA

Personal Author(s) : Ver, Istvan L. ; Dignan, Michael

PDF Url : ADA293277

Report Date : JUN 1994

Pagination or Media Count : 65

Abstract : In the framework of the U.S. Air Force's Advanced Technology Active Noise Reduction Initiative - an experimental program was carried out to demonstrate the feasibility of a new concept of an Active Liner. Using a 1:4 scale model of a jet engine test cell augmenter 8 dB to 15 dB reduction of the low frequency (8 Hz to 80 Hz at full scale) was obtained by inserting one or two active liner segments into a typical lined augmenter. The topics covered in this report include: (1) problems caused by low frequency noise and their land use implications, (2) description of the active liner concept, (3) control strategies employed, (4) description of the model-scale augmenter including passive and active sections and the feedback control system, (5) experimental results, (6) full-scale ramifications and (7) risk assessment of full-scale implementation.

Descriptors :   *JET ENGINE EXHAUST, *JET ENGINE NOISE, CONTROL, CONTROL SYSTEMS, RISK, STRATEGY, SCALE MODELS, PASSIVE SYSTEMS, TEST EQUIPMENT, JET ENGINES, LININGS, FEEDBACK, ENGINES, NOISE, LAND USE, LOW FREQUENCY.

Subject Categories : Acoustics
      Jet and Gas Turbine Engines

Distribution Statement : APPROVED FOR PUBLIC RELEASE