Abstract
This paper reviews recent advances in our understanding of the structure of turbulent nonpremixed flames due to extensive data acquired from single-point and planar imaging experiments using the Raman, Rayleigh, and LIF diagnostic methods. These techniques, used either separately or jointly, have become standard tools in combustion research. Flames with simple streaming flows as well as complex flows with recirculating zones are discussed for a variety of fuel mixtures and a range of turbulent mixing rates. The chemistry—turbulence interaction and other related issues like local flame extinction and the bimodality of the approach toward blowoff are discussed. Additional single-point data are also presented illustrating the effects of partially premixing the fuel with air, diluting it with nitrogen or adding methane to a mixture of nonhydrocarbon fuels. The bimodality of the conditional pdfs of various reactive scalars as the flames approach blowoff, and the start of occurrence of localized extinction, are correlated with two simple parameters: (a) the stoichiometric mixture fraction, ξ s , and (b) the reaction zone width, Δξ R . The latter parameter may be easily determined from standard laminar flame calculations for a given fuel mixture.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.