Aeroacoustic characterization of free jets
Abstract
The paper describes the methods pursued by one research group to characterize sources of aircraft engine noise. The methods used were (1) IR radiometry, which is sensitive to temperature fluctuations, (2) laser schlieren method, giving data proportional to components of the density gradient, (3) Doppler laser anemometry, and (4) fluorescence diffusion measurements to deduce mean and fluctuating concentration. Complex measurements by more than one technique and employing crossed paths were experimented with, in order to reveal the complementary possibilities of the methods. By means of a principle of scale separation and suitable data evaluation methods, reliable statements about noise sources could be obtained.
- Publication:
-
La Recherche Aerospatiale
- Pub Date:
- October 1978
- Bibcode:
- 1978ReAer......251E
- Keywords:
-
- Aeroacoustics;
- Flow Measurement;
- Free Jets;
- Jet Aircraft Noise;
- Jet Exhaust;
- Noise Measurement;
- Aerothermodynamics;
- Density Measurement;
- Flow Stability;
- Flow Visualization;
- Infrared Radiometers;
- Laser Anemometers;
- Noise Reduction;
- Turbulence;
- Acoustics