High Velocity Jet Noise Source Location and Reduction. Task 6. Noise Abatement Nozzle Design Guide.
Final rept. Jul 73-Aug 78,
GENERAL ELECTRIC CO CINCINNATI OH AIRCRAFT ENGINE BUSINESS GROUP
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Quantitative and qualitative guidance is provided in selecting noise abatement nozzle designs, applicable to high jet velocity engines andor supersonic cruise vehicles, to meet specific requirements. The fundamentals of jet noise mechanisms are reviewed, and basic, quantitative, design guide tools are provided. Techniques are presented for estimating suppressor acoustics and aerodynamic performance, mechanical design impact on engine installation, and how various suppressor designs impact aircraft mission in the course of maintaining acceptable sideline and community noise levels. Aerodynamic and acoustic performance and installation penalties may be evaluated based on empirical correlations. Guidelines to minimize exhaust system size consistent with flow and supersonic-expansion requirements and to combine other functional operations with nozzle flow area and expansion control hardware are included. Two independent, acoustic-prediction methods were developed to perform complementary functions. An empirical model, supplemented by guidelines based on experience in designing multielement suppressors, is provided. The model covers a wide range of nozzle geometries and provides quantitative estimates of the acoustic characteristics of a given suppressor nozzle design. A complementary, theoretical, jet-noise-prediction method is more restricted in terms of nozzle geometries which can be properly modeled but provides more details of the aerodynamic flow field and the component acoustic mechanisms. Author
- Jet and Gas Turbine Engines