Laser Imaging in the Stabilisation Region of Turbulent Lifted Flames
| Autor: | J. B. Kelman, Assaad R. Masri, A. J. Eltobaji |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Entrainment (hydrodynamics)
Jet (fluid) business.industry Turbulence Chemistry General Chemical Engineering Diffusion flame General Physics and Astronomy Energy Engineering and Power Technology General Chemistry Mechanics Vortex Physics::Fluid Dynamics Fuel mass fraction symbols.namesake Fuel Technology Optics Extinction (optical mineralogy) symbols Physics::Chemical Physics Rayleigh scattering business |
| Zdroj: | Combustion Science and Technology. 135:117-134 |
| ISSN: | 1563-521X 0010-2202 |
| DOI: | 10.1080/00102209808924153 |
| Popis: | The stabilisation region of turbulent lifted flames of methane has been investigated using simultaneous laser imaging of Rayleigh scattering, Raman scattering and OH·LIF. These images are used to derive mixture fraction, temperature, fuel mass fraction and OH concentration images. This enables the mixing field and the reaction zone of the lifted flames to be studied in detail. The images reveal that the oscillation in the lift off height of these flames may be caused by large scale vortices in the fuel jet pushing out into the reaction zone and causing entrainment of ambient coflowing air around the base of the reaction zone subsequently shifting it further downstream. It is proposed that the flame is stabilised through a combination of premixed propagation into fresh mixture and extinction due to the interaction of large scale turbulent structures in the jet. The large scale structures cause extinction by drawing ambient airin the base of the stabilisation region and convecting the reaction zone downstre... |
| Databáze: | OpenAIRE |
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