A LOI-RCCE methodology for reducing chemical kinetics, with application to laminar premixed flames

A framework for automated development of reduced mechanisms is presented by combining the methodologies of level of importance (LOI) and rate-controlled constrained equilibrium (RCCE). It is shown that these methods are complimentary, as they deal with different aspects of the overall reduction problem: LOI is a method of determining the species governed by fast/slow scales, while RCCE is a physical model that yields ODEs that describe the reduced model for a given selection. The potential for the synergy of the two methods is demonstrated by reducing a comprehensive mechanism for propane combustion (117 species, 665 reactions) and applying the reduced mechanism to the problem of 1-D laminar flame propagation. Results show that RCCE yields substantial CPU gainings, while predicting the major species as well as important minor species (such as radicals and C₂H₂) with sufficient accuracy.