Accession Number:

ADA094295

Title:

High Velocity Jet Noise Source Location and Reduction. Task 3 - Experimental Investigation of Suppression Principles Volume III - Suppressor Concepts Optimization

Descriptive Note:

Final Rept. Oct 1974-Oct 1977

Corporate Author:

FEDERAL AVIATION ADMINISTRATION WASHINGTON DC SYSTEMS RESEARCH AND DEVELOPMENT SERVICE

Report Date:

1978-12-01

Pagination or Media Count:

171.0

Abstract:

Experimental investigations were conducted of suppression principles, including developing an experimental data base, developing a better understanding of jet noise suppression principles, and formulating empirical methods for the acoustic design of jet noise suppressors. Acoustic scaling has been experimentally demonstrated, and five optimum nozzles have been selected for subsequent anechoic free-jet testing. Several studies were conducted to attempt an optimization of suppressor concepts. Trade studies of performance versus suppression, aircraft integration studies, and development of a figure- of-merit method of analysis all make up the activities in this optimization process. The end product of this effort was to design five nozzles for static and free-jet testing. Demonstration of acoustic scaling for several suppressor configurations was conducted to assure the adequacy of using scale-model results to project full-scale suppression levels. Full-scale data were obtained on several suppressor configurations using J79 and J85 engines. Scale-model data were obtained for these same configurations to allow comparison of scale-model and full-scale results.

Subject Categories:

  • Acoustics
  • Fluid Mechanics
  • Jet and Gas Turbine Engines

Distribution Statement:

APPROVED FOR PUBLIC RELEASE