Turbulence and Mixing in Turbulent Premixed Flames : Fine Flame Structure and Its Influence on Mixing Processes

抄録

Confined turbulent premixed flames stabilized by a pilot flame were investigated to elucidate the local fine structure of flames and its influence on mixing processes in the combustor. The fine flame structure was classified on the basis of the measured turbulence characteristics, and the probability density functions (PDF's) of local fluctuating velocity and temperature were examined in detail. A plateaulike distribution in the temperature PDF, which may correspond to a "distributed reaction zone", was observed in a limited portion of the flame in addition to a typical bimodal distribution corresponding to the structure of a "wrinkled laminar flame" or "laminar flamelets". The influence of the fine flame structure on the mixing processes was examined using an inert gas tracer.