Abstract
Experimental and chemical modeling studies of a 60 torr NH 3 /N 2 O/Ar flame were performed to provide furthert testing and refinments of a detailed chemical mechanism developed previously in our laboratory. This mechanism which is denoted as VS, consists of 87 reactions and 20 species. Flame temperatures were measured with a coated, thin-wire thermocouple and by rotational analyses of OH and NH laser induced fluorescence (LIF) spectra. Species concentration profiles of NH 3 , N 2 O, N 2 , H 2 O, NO, O 2 , NH. O 2 and OH were recorded using molecular beam mass spectrometry (MB/MS), LIF, or both. The experimental species concentrations were compared with those obtained with both equilibrium and PREMIX flame code calculations. The NH 3 /N 2 O mixture equilibrium calculations agree very well with both the PREMIX and measured postflame N 2 and H 2 O concentrations but underpredict the postflame NO concentration and overpredict the O 2 concentration. The PREMIX calculations predict very well the shapes of the experimental NH 3 , N 2 O, N 2 , H 2 O, NO, OH, and NH profiles throughout the flame but do not adequately predict the shape of the O-atom profile and overpredich the O 2 concentration by ≈60% at 1625 mm, suggesting that the VS mechanism requires some refinement. A modified mechanism, VS-modified, which provides better agreement with the experimental results, is proposed. In this mechanism the rate constants of the following reactions are altered to the limit of their experimental or calculated meertamties: (1) N 2 O+H=OH+N 2 (2) NH 2 +O=HNO_H, (3) NH 2 +OH=NH+H 2 O, (4) NH 2 +H=H 2 +NH, (5) NH 3 +OH=NH 2 +H 2 O, and (6) NO+H+M=HNO+M
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call