chemiluminescence study at low and elevated pressures

Chemiluminescence experiments have been performed to assess the state of current kinetics modeling. The difficulty with modeling lies in its broad emission spectrum, making it a challenge to isolate it from background emission of species such as CH ∗ and CH 2 O ∗ . Experiments were performed in a mixture of 0.0005H 2 +0.01N 2 O+0.03CO+0.9595Ar in an attempt to isolate emission. Temperatures ranged from 1654 K to 2221 K at two average pressures, 1.4 and 10.4 atm. The unique time histories of the various chemiluminescence species in the unconventional mixture employed at these conditions allow for easy identification of the concentration. Two different wavelengths to capture were used; one optical filter was centered at 415 nm and the other at 458 nm. The use of these two different wavelengths was done to verify that broadband was in fact being captured, and not emission from other species such as CH ∗ and CH 2 O ∗ . As a baseline for time history and peak magnitude comparison, OH ∗ emission was captured at 307 nm simultaneously with the two filters. The results from the two filters were consistent with each other, implying that indeed the same species (i.e., ) was being measured at both wavelengths. A first-generation kinetics model for and CH 2 O ∗ was developed, since no comprehensively validated one exists to date. CH 2 O ∗ and CH ∗ were ruled out as being present in the experiments at any measurable level, based on calculations and comparisons with the data. Agreement with the model was only fair, which necessitates future improvements for a better understanding of chemiluminescence as well as the kinetics of the ground state species.