The structure of the recirculation zone of a bluff-body combustor
- Univ. of Sydney (Australia). Dept. of Mechanical and Mechatronic Engineering
- Sandia National Labs., Livermore, CA (United States). Combustion Research Facility
- Systems Research Labs., Inc., Dayton, OH (United States)
The instantaneous mixing and reactive scalar fields have been measured in the recirculation zones of turbulent non-premixed flames stabilized on a bluff body, using the spontaneous Raman scattering technique. The measured means and rms fluctuations of mixture fraction, temperature, and the mass fractions of stable species are presented for various axial locations in the recirculation zone of CH{sub 4}/CO and CH{sub 4}/H{sub 2} flames. The diameters of the bluff body and the central fuel jet are 50 and 2 mm, respectively. Both flames are about 40 cm in length and have a full, luminous recirculation zone that extends for about one bluff-body diameter from the exit plane. Two regions of almost homogeneous mixture are identified within the recirculation zone: A large outer region, which on average is fuel lean, and an inner region, which is smaller and closer to the central fuel jet. Combustion is more intense in the inner region, where mean mixture fraction is stoichiometric and the peak values for temperature and mass fractions of combustion products are reached. Finite-rate chemical kinetic effects exist but not a high enough levels to cause localized extinction in the recirculation zone.
- OSTI ID:
- 93282
- Report Number(s):
- CONF-940711--
- Country of Publication:
- United States
- Language:
- English
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