Flow structure and combustion in nonpremixed turbulent bluff-body stabilized flames
The flow structures and combustion characteristics of bluff-body stabilized flames were studied using planar flow visualization and direct flame photography. In the planar flow visualization the fuel was seeded with alumina particles and a thin sheet of laser light was used to illuminate the field of view. Mie scattering from the particles in the illuminated plane was then recorded on photographic film. For fixed fuel velocity and low air velocity the particle streak photographs showed a three-dimensional vortical flow structure near the burner face that acted to stabilize the flame at the bluff-body face. For high air velocity, the vortical structures were not observed and the flames were detached. In this case, the fuel jet stagnates on the axis, which stabilizes the flame away from the burner face. Short-exposure Mie scattering images were used to provide detailed information about the turbulent structures that occur in bluff-body flames. These structures can be large, irregular and time varying. It is concluded that instantaneous planar imaging diagnostic techniques are very useful for the characterization of these flames. The experimental results obtained in this study are anticipated to provide new insight into the combustion characteristics of bluff-body flames, insight that should prove useful in developing the next generation of computer models describing such flames. 8 refs., 6 figs., 4 tabs.
- Research Organization:
- Sandia National Labs., Livermore, CA (USA)
- DOE Contract Number:
- AC04-76DR00789
- OSTI ID:
- 7158813
- Report Number(s):
- SAND-86-8695; CONF-860804-17; ON: DE88011807
- Resource Relation:
- Conference: 21. international symposium on combustion, Munich, F.R. Germany, 3 Aug 1986
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
FLAMES
COMBUSTION PROPERTIES
FLOW MODELS
FLOW VISUALIZATION
STREAK PHOTOGRAPHY
COMBUSTION
FLAME PROPAGATION
FUEL INJECTION SYSTEMS
FUEL-AIR RATIO
GAS FLOW
IGNITION
MIXING
TURBULENT FLOW
CHEMICAL REACTIONS
FLUID FLOW
FUEL SYSTEMS
MATHEMATICAL MODELS
OXIDATION
PHOTOGRAPHY
THERMOCHEMICAL PROCESSES
421000* - Engineering- Combustion Systems