Development of a coherent flamelet model for a spark-ignited turbulent premixed flame in a closed vessel

Abstract

Three-dimensional calculations of turbulent combustion which include ignition, laminar and turbulent flame propagation and quenching at the wall are performed by the coherent flamelet model (CFM). The existing CFMs in the literature are tested and new forms are proposed. A mean stretch factor I-o is introduced to consider the stretch and curvature effects of turbulence. Quenching at the wall is simulated by the simple wall flux model (SWFM) of the flame surface density. Two forms of the flame production term, CFM-1 and CFM-2, are tested to show the predictive capability of the CFM for turbulent burning velocity. CFM-1 has the flame production term given by the average rate of strain proposed by Cant ct at. [20], while CFM-2 has the production term proportional to the rms turbulent velocity. It turns out that the turbulent burning velocity of CFM-2 is in reasonable agreement with the data of Checkel and Thomas and Bradley's correlation with variation of the Karlovitz number, rms turbulent velocity, and integral length scale. (C) 1998 by The Combustion Institute.