Measurement and Kinetics Prediction of Undiluted Methane–Oxygen Laminar Flame Speeds

Abstract

This study presents new laminar flame speed () data for a wide range of equivalence ratios () at low pressure (0.5 atm) and multiple initial pressures (0.5–3 atm) at an equivalence ratio far from stoichiometry (). All experiments were conducted at room temperature using spherically expanding flames. At 0.5 atm, peaked slightly lean, reaching a maximum of 411 cm/s near . Far from stoichiometry, was approximately 72 and 34 cm/s at and 2.4, respectively. predictions were computed using several commonly cited chemical kinetics mechanisms for methane combustion, with performance approximately the same for all mechanisms. Every mechanism underpredicted at 0.5 atm for , with performance especially poor near stoichiometry ( underprediction near the peak). For , experiments were conducted for pressures from 0.5 to 3.0 atm, showing that varies approximately according to the power law . The mechanisms captured this pressure dependency, with GRI-Mech 3.0 performing especially well. Sensitivity analysis shows that many reaction adjustments are necessary to solve the underprediction near stoichiometry, with potentially a reaction of interest.