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Hydroxyl and its concentration profile in methane-air flames
Applied Optics
|March 11, 2010
Summary
Researchers measured hydroxyl concentration profiles in flames using laser-induced fluorescence. The study provides the first quantitative comparison of these profiles to flame models, finding negligible electronic-excited state influence on flame structure.
Area of Science:
- Combustion Science
- Chemical Physics
- Spectroscopy
Background:
- Understanding flame chemistry is crucial for combustion efficiency and safety.
- Hydroxyl radicals play a key role in combustion processes.
- Accurate flame models require precise species concentration data.
Purpose of the Study:
- To quantitatively compare measured hydroxyl concentration profiles with advanced flame models.
- To investigate the influence of hydroxyl on fuel breakdown and CO oxidation.
- To present the first optical measurements of atmospheric-pressure flame reaction zones.
Main Methods:
- Measurements of hydroxyl concentration profiles using laser-induced fluorescence (LIF).
- Determination of absolute mole fraction concentrations via normalization to laser absorption measurements.
- High spatial resolution (100-microm) optical measurements of flame reaction zones.
Main Results:
- Hydroxyl concentration profiles were successfully measured in atmospheric-pressure premixed laminar flames.
- Quantitative comparison with recent flame models was performed.
- The electronic-excited state of hydroxyl was found to have a negligible influence on flame structure.
Conclusions:
- The study validates current flame models by comparing them with experimental hydroxyl concentration data.
- Laser-induced fluorescence offers high-resolution insights into flame reaction zones.
- Experimental data support the assumption of negligible electronic-excited state effects of hydroxyl on flame structure.
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