New experimental studies on jet noise amplification
Abstract
Experimental results on jet noise amplification by internal acoustic excitation are presented for hot subsonic model jets, supersonic jets and coaxial jets. Threshold excitation level, Strouhal number of peak sensitivity, amplification directivity are analyzed as a function of temperature for subsonic single flow jets. The effects of acoustic excitation on jet mixing noise, and shock associated noise are demonstrated for fully expanded and underexpanded supersonic jets. Results obtained on coaxial jets show that secondary flow inhibits primary jet sensitivity to internal excitation. Practical implications of these excitation experiments on model jets close to real jet exhaust conditions are briefly discussed.
- Publication:
-
American Institute of Aeronautics and Astronautics Conference
- Pub Date:
- June 1980
- Bibcode:
- 1980aiaa.confQ....J
- Keywords:
-
- Acoustic Excitation;
- Aeroacoustics;
- Jet Aircraft Noise;
- Noise Spectra;
- Sound Amplification;
- Subsonic Flow;
- Acoustic Ducts;
- Engine Noise;
- Exhaust Gases;
- Jet Flow;
- Scale Models;
- Strouhal Number;
- Temperature Effects;
- Acoustics