Accession Number:

ADA094292

Title:

High Velocity Jet Noise Source Location and Reduction. Task 2 Supplement. Computer Program for Calculating the Aeroacoustic Characteristics of Jets form Nozzles of Arbitrary Shape.

Descriptive Note:

Final rept. for period ending Oct 77,

Corporate Author:

GENERAL ELECTRIC CO CINCINNATI OH AIRCRAFT ENGINE GROUP

Personal Author(s):

Report Date:

1978-05-01

Pagination or Media Count:

145.0

Abstract:

A computational procedure is presented for predicting the aerodynamic and acoustic characteristics of jets from nozzles of arbitrary shape. The procedure treats the jet plume as a collection of uncorrelated multipole sound sources which convect with the flow. The aerodynamic characteristics of the jet are evaluated utilizing an extension of Reichardts theory for free turbulent flows. The acoustic radiation from each of the sound sources is evaluated from high-frequency asymptotic solutions of Lilleys equation. The jet plume is subdivided into several hundred elemental volume sources, each roughly the size of a turbulent eddy volume. The correlated sound level spectra of the individual eddy volumes are summed on a mean-square pressure basis to yield the total turbulent mixing noise levels. An auxiliary calculation of shock-cell broadband noise is made and added to the turbulent mixing noise spectrum to give the total farfield noise. A description of the computational model and associated computer program is presented herein, along with a sample of input and output. A FORTRAN listing of the computer program is also included. Author

Subject Categories:

  • Computer Programming and Software
  • Acoustics
  • Fluid Mechanics
  • Jet and Gas Turbine Engines

Distribution Statement:

APPROVED FOR PUBLIC RELEASE