Accession Number : ADP007527

Title :   Identifying the Principal Noise Sources of Fixed-Wing Combat Aircraft in High-Speed Flight,

Corporate Author : DEFENCE RESEARCH AGENCY FARNBOROUGH (UNITED KINGDOM) AEROSPACE DIV

Personal Author(s) : Bryce, W. D. ; Pinker, R. A. ; Strange, P. J.

Report Date : APR 1992

Pagination or Media Count : 20

Abstract : Before considering means for alleviating the noise from modern military combat aircraft operating in highspeed low-level flight, it is important to identify the principal noise sources. To this end, a carefully-controlled flight test programme has been carried out using a Tornado aircraft (in standard training configuration) operating at flight speeds from 0.5M to 0.8M. The major sources of the aircraft noise, airframe noise, installed jet mixing noise and jet shock noise, have been successfully identified, quantified and correlated. Although the jet mixing noise tends to be the major source at low flight speeds, and the shock noise at high flight speeds, all three sources are comparable in magnitude during the rapid rise-time of the noise signal and at its peak. Indeed, were it possible to reduce greatly both the jet mixing and shock noise, the peak noise levels would only reduce by about 5 dBA.

Descriptors :   *JET AIRCRAFT NOISE, *AIRCRAFT ENGINE NOISE, *MILITARY AIRCRAFT, *FIXED WING AIRCRAFT, AIRCRAFT, AIRCRAFT NOISE, AIRFRAMES, FLIGHT, FLIGHT SPEEDS, LEVEL FLIGHT, LOW LEVEL, MIXING, NOISE, SHOCK, SIGNALS, STANDARDS, TEST AND EVALUATION, TIME, TORNADOES, TRAINING, VELOCITY, WARFARE, HIGH VELOCITY.

Subject Categories : Acoustics
      Military Aircraft Operations

Distribution Statement : APPROVED FOR PUBLIC RELEASE