Soon Muk Hwang

Recombination of methyl radicals at high temperatures

Abstract The recombination of methyl radicals generated by pyrolysis of azomethane-Ar mixtures and detected by coincidence absorption of the zinc 213.9 nm atomic line was studied in incident shock waves at temperatures from 1300 to 1700 K and densities from 2 × 10 −6 to 9 × 10 −6 mol/cm 3 . A simultaneous regression analysis based upon large factorial design computer simulations was used to solve the inverse problem of parameter identification and to determine optimal values of rate coefficient and other parameters. The rate coefficient found for the recombination channel is in agreement with a previously published nine-parameter weak collision model.

Rate coefficient of the O + H2 = OH + H reaction determined via shock tube-laser absorption spectroscopy

Abstract The rate coefficient for the reaction O + H 2 = OH + H was determined via OH profile measurements in a lean H 2 /O 2 /Ar mixture behind reflected shock waves. Over the temperature range 1424–2427 K our expression is k 2 = (1.88 ± 0.07) × 10 14 exp(−6897 ± 53 K/ T ) cm 3 mol −1 s −1 . We do not support strong curvature in the rate expression for this temperature range.