Reduced chemistry for hydrogen and methanol premixed flames via RCCE

The method of Rate-Controlled Constrained Equilibrium (RCCE) provides a general and physically sound mathematical description of the dynamics of a chemical system, of which several species are assumed to be kinetically controlled and others equilibrated. In this paper we present an RCCE study of premixed hydrogen–air and methanol–air flames for a wide range of equivalence ratios, and burning velocity and detailed flame structure for both major and minor species are investigated. We also investigate the suitability of employing the species appearing in conventional reduced mechanisms as constraints, drawing an analogy between the constrained species in RCCE and the non-steady-state species in conventional reduced mechanisms. In particular, the RCCE mechanism is derived from a 63-species comprehensive mechanism of Lindstedt and co-workers and selection of constraints is carried out in accordance with the non-steady-state species employed in a systematically reduced mechanism for methanol derived from the same comprehensive mechanism. Most of the species are very well predicted both at stoichiometric and rich/lean limits.

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