Ignition Delay Times of Methane and Hydrogen Highly Diluted in Carbon Dioxide

Abstract

As part of the effort to understand oxy-fuel combustion with large CO2 dilution, we have measured shock tube ignition delay times for methane/O2/CO2 mixtures and hydrogen/O2/CO2 mixtures. Ignition delay times (IDT) were measured using sidewall pressure and OH* emission near 306 nm. IDT measurements were performed near 80 atm for 3.91% methane/9.92% oxygen/carbon dioxide mixtures and near 110 atm for 7.5% methane/15% oxygen/carbon dioxide mixtures. IDT measurements for 10% hydrogen/5% oxygen/carbon dioxide mixtures were also performed near 110 atm. IDT measurements were compared to several current mechanisms. Excellent agreement was seen between the ARAMCO and USC Mech 2 models and the data under the current operating conditions.