A shock-tube study of the oxidation of C 2H 6/O 2/Ar and C 2H 6/SiH 4/O 2/Ar mixtures
Conference Paper
Overview
Overview
abstract
Ethane ignition and oxidation behind reflected shock waves with and without silane addition were studied using several dilute mixtures of varying concentrations and equivalence ratios (0.5 < < 2.0). The C 2H 6/SiH4/O2/Ar mixtures were studied at temperatures and pressures between 1230-1862 K and 0.9-3.0 atm, respectively. Argon dilution ranged from 91-98%. The reaction process was studied by monitoring the A 2 + X 2 chemiluminescence emission from the hydroxyl radical near 307 nm. In this study and in several previous studies, there have been different ways of obtaining the ignition delay time both in terms of diagnostics and in definition. A summary of the different techniques is given and used to make fair comparisons with other studies. A correlation of ignition delay time with temperature and concentration is proposed and compared with previous studies. This correlation has an r 2 value of over 0.98, mainly due to the inclusion of an argon concentration dependency. The overall activation energy for ethane ignition was found to be 36.0 kcal/mol over the range of conditions studied. Consistency of the data with previous ignition experiments is discussed. The experimental results indicate that silane addition to an ethane mixture at levels as low as 20% of the fuel can create up to a 50% reduction in ignition delay time for fuel-lean mixtures at high temperatures. It also created a reduction of about 22% for stoichiometric mixtures. Comparison of the present ethane-only ignition data with results from the literature highlights some of the differences in ignition definition, diagnostics, and range of conditions amongst the different studies. 2004 by the American Institute of Aeronautics and Astronautics. Inc.
