Ignition Time Measurements for Methylcylcohexane- and Ethylcyclohexane-Air Mixtures at Elevated Pressures

The ignition of methylcyclohexane (MCH)/air and ethylcyclohexane (ECH)/air mixtures has been studied in a shock tube at temperatures and pressures ranging from 881 to 1319 K and 10.8 to 69.5 atm, respectively, for equivalence ratios of 0.25, 0.5, and 1.0. Endwall OH* emission and sidewall pressure measurements were used to determine ignition delay times. The influence of temperature, pressure, and equivalence ratio on ignition has been characterized. Negative temperature coefficient behavior was observed for temperatures below 1000 K. These measurements greatly extend the database of kinetic targets for MCH and provide, to our knowledge, the first ignition measurements for ECH. The combination of the MCH measurements with previous shock tube and rapid compression machine measurements provides kinetic targets over a large temperature range, 680-1650 K, for the validation of kinetic mechanisms. (C) 2008 Wiley Periodicals, Inc. Int J Chem Kinet 41: 82-91, 2009