Acoustic emission from coherent structures in a turbulent jet
Abstract
Measurements of turbulence properties for determining the acoustic far field radiated by a hot free jet in the subsonic range were carried out using radiometers detecting the local infrared emission of the jet. Results were in good agreement with others of the same type but obtained in different ways, in revealing the existence of large-scale motion patterns associated with the instability properties of the jet mixing zone. An experimentation procedure based on analysis of spectral relations between the infrared signal fluctuations and the fluctuations of microphone signals picked up in the near and far pressure fields was therefore devised, and enabled these coherent structures and the sound field associated with them to be determined.
- Publication:
-
Acoustic emission from coherent structures in a turbulent jet Transl. into ENGLISH of "Emission Acoustique de Struct. Coherentes dans un Jet Turbulent
- Pub Date:
- March 1977
- Bibcode:
- 1977aecs.rept.1976D
- Keywords:
-
- Acoustic Excitation;
- Acoustic Measurement;
- Sound Generators;
- Turbulent Jets;
- Far Fields;
- Infrared Radiation;
- Jet Exhaust;
- Jet Flow;
- Microphones;
- Radiation Sources;
- Radiometers;
- Acoustics