Accession Number : AD0727345

Title :   Effective Source Distribution in a Choked Screech Jet,

Corporate Author : NATIONAL AERONAUTICAL ESTABLISHMENT OTTAWA (ONTARIO)

Personal Author(s) : Lee,B. H. K. ; Westley,R.

Report Date : MAY 1971

Pagination or Media Count : 43

Abstract : Using experimental measurements of the sound pressure and phase in the near field of a choked screech jet, a method is proposed for computing the effective source positions, their strengths and phases. Two models are considered. The first assumes a distribution of point sources along the jet axis and the second assumes ring sources along the jet boundary instead. A technique of minimization due to Powell is used and a solution is obtained when the sum of squares reaches a minimum. Results for a choked jet at a screech frequency of 3170 c/s are presented. (Author)

Descriptors :   (*AIRFRAMES, FATIGUE(MECHANICS)), (*JET ENGINE NOISE, AIRFRAMES), MATHEMATICAL ANALYSIS, MODEL TESTS, SUPERSONIC NOZZLES, TEST EQUIPMENT, SOURCES, NOISE GENERATORS, FEEDBACK, FLOW FIELDS, STATISTICAL DISTRIBUTIONS

Subject Categories : Aircraft
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE