GRI-Mech 1.2by including nitrogen chemistry relevant to natural gas chemistry and reburning. It contains 277 elementary chemical reactions of 49 species.
GRI-Mech 2.1, correcting two minor errors.
Version 2.11 contains the chemistry identical to that of version 1.2 but adds 102 reactions of 17 additional nitrogen-containing species. The parameters of the 175 reactions from version 1.2 were not varied in the course of the Version 2.11 optimization process except for the rate coefficient of the CH + H2O --> H + CH2O reaction, which was found to play an important role in prompt NO formation but to have no effect on the course of the carbon-hydrogen- oxygen chemistry of methane combustion. Version 2.11 is therefore identical to version 1.2 with respect to the carbon-hydrogen-oxygen chemistry of natural gas ignition and flames.
Version 2.11 was not optimized for modeling pure nitrogen- hydrogen-oxygen chemistry or any form of NOx removal process except for reburning.
In the course of developing
GRI-Mech 2.11 we learned quite
early that optimizing the nitrogen chemistry relevant to natural gas
flames and reburning is qualitatively a very different challenge than
optimizing the carbon-hydrogen-oxygen chemistry. In the first place, we
were able to locate only a much smaller data base of experimental
information from which to draw optimization targets.
Then, once the modeling process had proceeded far enough that we could
examine matches between computed and observed behavior, we found a far
higher degree of discord among the matches to targets and other data
than we had seen in working with our earlier optimizations of
carbon-hydrogen-oxygen chemistry. We therefore have to caution users of
GRI-Mech 2.11 to regard it only a preliminary starting
point that can not be applied with anything like the degree of
confidence that can be attached to the
carbon-hydrogen-oxygen chemistry. We do believe that
GRI-Mech 2.11 is an improvement for the experiments modeled over
previous attempts to describe NOx formation and removal in natural gas
example the 1989 Miller and Bowman mechanism, and are therefore releasing it at
this time in the spirit of 'beta testing' our first optimized result and
stimulating further experimental study of NOx formation and removal in natural
load to diskoption in your Web browser)
|grimech211.dat||A reaction mechanism and
rate coefficient file,
|thermo211.dat||A thermochemical data file to be used with
|readme211.dat||Same as the present home page|
|transport.dat||A file containing the parameters needed for calculating transport coefficients to be used in the Sandia flame code|
|bugfix.dat||A file containing selected user questions, comments, and
suggestions related to the implementation of
unix.sri.com, the directory
GRI-Mech 2.11, please refer to this Web page: C.T. Bowman, R.K. Hanson, D.F. Davidson, W.C. Gardiner, Jr., V. Lissianski, G.P. Smith, D.M. Golden, M. Frenklach and M. Goldenberg,
|NF1||Maximum NO concentration||SRI Flame: Heard, D.E., et al.,
Combust. Flame 88:137 (1992)
|NF2||Location of CH maximum|
|NFR1||HCN relative concentration||Flow Reactor: Glarborg, P., and Miller, J.A.,
Combust. Flame 99:475 (1994)
|NFR2||NO relative concentration|
|NFR3||N2O relative concentration|
|NF6||Maximum NO mole fraction||Sandia Flame: Miller, J.A., et al.,
20th Symp. Int. Combust., 1984, p. 673
|NF7||Maximum CN mole fraction|
|NF8||Maximum CH mole fraction||UTRC Flame: Zabielski, M.F. and Seery, D.J.,
GRI Report 84/0126, 1984
|NF9||Maximum CN mole fraction|
|NF11||Ratio of CH peak concentrations at two levels of NO doping||NRL Flame: Williams, B.A., and Fleming, J.W.,
Combust. Flame 98:93 (1994)
CH4-O2-Ar-NO or N2O
|NF12/13||Ratio of CN peak concentrations for NO and N2O doping|
GRI-Mech 2.11for this target.
GRI-Mech 2.11is identical to
GRI-Mech 1.2with respect to the carbon-hydrogen-oxygen chemistry of natural gas ignition and flames.
Here is a list of the validation checks of Version 2.11 that we have made (measurement uncertainties, when reported by the cited investigators, are indicated):