Flame stabilization in a supersonic combustor with hydrogen injection upstream of cavity flame holders: experiments and simulations
Författare
Summary, in English
Experimental observations and numerical simulation were conducted to study the flame characteristics and flame stabilization mechanism in a supersonic combustor with hydrogen injection upstream of cavity flame holders. OH radical distribution of the reacting flowfield was obtained using OH spontaneous emission and OH-PLIF (planar laser-induced fluorescence). The supersonic combustion flowfield with L/D = 7 cavity was calculated by large eddy simulation. The turbulence-combustion interaction model was based on a partially premixed flamelet model with a level-set approach. The results showed that hydrogen fuels were transported into the cavity shear; lean mixture and rich mixture were produced in the internal cavity and the declining jet, respectively. An approximately steady partially premixed flame front exists in the cavity shear layer. The flame front propagates and extends to the region around the fuel jet due to the interaction of counter-rotating vortices induced by the jet with the cavity shear layer. The flame front sustained in the shear layer likely penetrates the jet core and ignites the whole jet. Behind the flame front, most of the jet beam is burned as diffusion flames. The physical process of the flame stabilization demonstrated the similarity with triple flame characteristics, which indicted that triple flame theory might be the basic flame stabilization mechanism of the cavity flame holders.
Avdelning/ar
Publiceringsår
2011
Språk
Engelska
Sidor
1351-1365
Publikation/Tidskrift/Serie
Proceedings of the Institution of Mechanical Engineers. Part G: Journal of Aerospace Engineering
Volym
225
Issue
G12
Dokumenttyp
Artikel i tidskrift
Förlag
SAGE Publications
Ämne
- Fluid Mechanics and Acoustics
Nyckelord
- flame stabilization
- cavity flameholder
- large eddy simulation
- partially premixed flamelet model
- triple flame
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 0954-4100