Cavity Ring-Down Spectroscopy and Intracavity Laser Absorption Spectroscopy were used to measure the concentration profiles of NH and NH2 at 30 torr methane/oxygen/nitrogen flames doped with small amount of N2O. These absorption spectroscopy methods displayed high sensitivity (4 x 1010 cc for NH and 8 x 1010 cc for NH2). The absolute NH concentrations were in agreement with those predicted by GRI-Mech 2.11 mechanism and one-dimensional PREMIX code. The absolute NH2 concentrations in the lean flame also agreed well with calculations, but the observed concentrations in the stoichiometric and rich flames were about twice the calculations. In the rich flame, the calculations underpredicted the NH concentrations at large distances from the burner. The strong spectra of NH2 were observed even at 40 nm above the burner where the model calculations predicted very insignificant NH2 concentration. The discrepancy was attributed to limitations of both the chemical mechanism and one-dimensional PREMIX code used for calculations.
|Number of pages||1|
|Journal||International Symposium on Combustion Abstracts of Accepted Papers|
|State||Published - 2000|
|Event||28th International Symposium on Combustion - Edinburgh, United Kingdom|
Duration: 30 Jul 2000 → 4 Aug 2000