Investigation of kinetics of iso-octane ignition under scramjet conditions

• Published in: International journal of chemical kinetics Vol. 38; no. 3; pp. 194 - 201
• Main Authors: Kahandawala, Moshan S. P., Corera, Shehan A. P., Williams, Skip, Carter, Campbell D., Sidhu, Sukh S.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.03.2006
• ISSN: 0538-8066; 1097-4601
• DOI: 10.1002/kin.20155

A single pulse reflected shock tube was used to investigate iso‐octane ignition over the temperature range of 900–1400 K at a pressure of ∼1 atm. To account for the anticipated long ignition delay times at the lower temperatures, long shock tube dwell times (∼12 ms) at lower temperature and near atmospheric pressure were achieved by using argon–helium mix as a driver gas. Chemical thermometer experiments were conducted to remove any uncertainties in determining postreflected shock temperatures. The ignition delay data obtained in this study are in good agreement (in the overlap region) with the iso‐octane ignition data from a previous shock tube study. However, the activation energy of iso‐octane ignition obtained in this study in the lower temperature region (<1300 K) is significantly smaller (∼15 kcal vs. ∼40 kcal) than that obtained in a previous higher temperature study. The deflagration may be responsible for lowering of activation energy under the conditions of this study. Two detailed iso‐octane kinetic models (Air Force Research Laboratory—AFRL and Curran et al.) were used to model the experimental results of this study. The AFRL mechanism showed a good agreement with the experimental iso‐octane ignition delays and their temperature dependence. © 2006 Wiley Periodicals, Inc. Int J Chem Kinet 38: 194–201, 2006