An Eight-Step Kinetics Mechanism for High Temperature Propane Flames

Abstract

An accurate eight-step kinetics mechanism for the high temperature oxidation of propane has been developed. This model is based on previous experimental research and has been developed in ignition delay studies and investigations of freely propagating and quenching flames. Results from a detailed kinetics model and available experimental data were used for comparison and verification of the multi-step model. One-dimensional transient calculations were performed at pressures ranging from one to 40 atmospheres, unburned gas/wall temperatures from 400 to 500 K, and propane-air equivalence ratios from 0·7 to 1·3. Shortcomings in the earlier four-step and eight-step models are identified and strategies for improvement of the simplified model are discussed. Based on this work, the original eight-step model is modified to improve representation of the induction region, flame speed, postflame region, wall-quench behavior, and unburned hydrocarbon evolution. Correlations which extend the model to a wider pressure range and fuel-rich equivalence ratios are developed. In addition, a sensitivity study which allows for significant improvement in the ignition delay behavior of the model is performed. The modified, eight-step model is proven to adequately reproduce the primary features of the detailed kinetics in both freely propagating and wall-quench environments while using a fraction of the computer time.