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
Distribution Statement : APPROVED FOR PUBLIC RELEASE