Accession Number : AD0700775

Title :   EDDY MACH WAVE NOISE FROM A SIMPLIFIED MODEL OF A SUPERSONIC MIXING LAYER.

Descriptive Note : Technical note,

Corporate Author : TORONTO UNIV (ONTARIO) INST FOR AEROSPACE STUDIES

Personal Author(s) : Ribner,H. S.

Report Date : OCT 1969

Pagination or Media Count : 18

Abstract : A simplified flow model is presented for simulating features of noise generation by supersonic jets and rockets. 'Eddy Mach waves' appear as a consequence of balancing internal and external pressures, and noise power may be estimated. Specifically, the turbulent mixing layer of a supersonic jet is modeled as a layer of two-dimensional square 'eddies'; this separates the main flow from fluid at rest and moves at an intermediate speed. (In an improved model the square eddies are replaced by a turbulent flow layer constrained by plane interfaces). The initially plane interfaces, because of unopposed internal pressures, will ripple slightly such that Mach waves arise and effect a pressure balance. The Mach wave noise pattern is readily calculated as well as the acoustic energy flux. (Author)

Descriptors :   (*AERODYNAMIC NOISE, SUPERSONIC CHARACTERISTICS), (*JETS, AERODYNAMIC NOISE), ROCKETS, MATHEMATICAL MODELS, TURBULENCE, TWO DIMENSIONAL FLOW, INTERFACES, PRESSURE, CANADA

Subject Categories : Aerodynamics
      Acoustics
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE