Affiliation:
1. University of Arizona
2. University of Illinois at Urbana-Champaign
3. Combustion Research and Flow Technology, Inc. (CRAFT Tech)
Abstract
We present experimental results using a swept-wavelength external
cavity quantum cascade laser (swept-ECQCL) diagnostic to measure
broadband absorption spectra over a range of 920−1180cm−1 (8.47–10.87 µm) with
2 ms temporal resolution in premixed hydrogen/oxygen flames
propagating inside an enclosed chamber. Broadband spectral fits are
used to determine time-resolved temperatures and column densities of H2O produced during combustion. Modeling
of the flowfield within the test chamber under both equilibrium
conditions and using a 1D freely propagating flame model is compared
with the experiment in terms of temporal dynamics, temperatures, and H2O column density. Outputs from the
numerical models were used to simulate radiative transport through an
inhomogeneous combustion region and evaluate the performance of the
spectral fitting model. Simulations show that probing hot-band H2O transitions in the high-temperature
combustion regions minimizes errors due to spatial inhomogeneity. Good
agreement is found between the experimental and modeling results
considering experimental uncertainties and model assumptions.
Funder
Defense Threat Reduction
Agency
Subject
Atomic and Molecular Physics, and Optics,Engineering (miscellaneous),Electrical and Electronic Engineering