Further experimental results on the structure and acoustics of turbulent jet flames
- Creators
- Kumar, R. N.
Abstract
The structure of open turbulent jet flames is experimentally studied in the context of their noise emission characteristics. The differences between premixed and (co-flow) non-premixed flames are explored. Recent experiments repeated in an anechoic chamber complement earlier results obtained in a hard-walled bay. The reactants (methane and enriched air) are burned in the premixed, or non-premixed, mode after a length of pipe flow (ℓ/D> 150). The thick-walled tubes anchor the flames to the tip at all of the velocities employed (maximum velocity, well over 300 ft/sec), thus eliminating uncertainties associated with external flameholders. The time-averaged appearance of the flames is obtained with still photographs (1160 sec). The detailed structures are revealed through high-speed (≈ 2500 frames/sec) motion pictures. The acoustic outputs of the flames are mapped with a condenser microphone. The recorded data are played back to obtain the amplitude, waveshapes, directionalities, and frequency spectra of the noise. Profound differences are found between the premixed and non-premixed flames in their structures and noise characteristics.
Additional Information
© American Institute of Aeronautics and Astronautics. Inc., 1975. The author continues to feel deeply grateful to the Solid Propellant Engineering Section at JPL for allowing the use of their experimental facilities. He specially thanks Mr. Warren Dowler for his enthusiastic encouragement at all stages. The author thanks Messrs. Emilio Sovero and David Daly for technical assistance and Mr. Paul Massier for allowing the use of the anechoic chamber. This research project was initiated by Professor F. E. C. Culick.Attached Files
Published - 223_Kumar_RN_1975.pdf
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Additional details
- Eprint ID
- 21398
- Resolver ID
- CaltechAUTHORS:20101216-111045073
- Created
-
2010-12-17Created from EPrint's datestamp field
- Updated
-
2019-10-03Created from EPrint's last_modified field
- Caltech groups
- Guggenheim Jet Propulsion Center
- Series Name
- AIAA Papers
- Series Volume or Issue Number
- AIAA 75-523
- Other Numbering System Name
- AIAA
- Other Numbering System Identifier
- 75-523