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Methane/air combustion

In this section, different mechanisms for methane/air combustion are presented. The choice depends upon your application range, your simulation tool and the quantities that are of interest to you:

You can find the datas provied on this page on the online database.

Please, note that unless explicitly specified, the output files provided in this website are a mean of comparison and are not necessarily formatted to be used as a restart file for cantera/can2av/...


Detailed mechanisms

The GRIMech 3.0 mechanism

This detailed mechanism for methane-air combustion is probably the most famous one. It is comprised of 325 reactions and 53 species. It is originally an optimized mechanism designed to model natural gas combustion, including NO formation and reburn chemistry. Detailed information about this standard mechanism can be found on this dedicated website. Here, you will also find the files in CHEMKIN format.


The GRIMech 2.11 mechanism

This detailed mechanism for methane-air combustion is an ancestor of the previous one, the GRIMech 3.0. It is comprised of 277 reactions and 49 species. Detailed information about this standard mechanism can be found on this dedicated website. Here, you will also find the files in CHEMKIN format.

If it is an "old" version, why bother ? It has been argued that with the newer 3.0 version, predicted levels of NO might be off, due to the production of too much NO. See, for example, Chapter 6 of the thesis of T. Jaravel.


Analytically reduced mechanisms

What differs with those type of mechanisms is that the source term of each species that remain is not expressed anymore as a combination of elementary reaction rates; but rather as a complex relation involving the detailed mechanism's reaction rates as well as the concentration of species that may not be amongst the reduced species set. Those mechanisms are characterized by the retained transported species, and are not associated with any "real" set of reactions, so that they require a special subroutine to override the classical evaluation of the species' source terms.

Lu and Law's mechanism with 19 species

This mechanism involves 19 species, and is derived from a 30 species skeletal mechanism for methane-air based on the GRIMech 3.0. The .cti file is available here. More information can be found on the website of Dr. Tiafeng Lu. In particular, the suitable kinetic routine for this ARC, as well as information about the 30 species skeletal mechanism, can be found on the website.


Lu and Law's mechanism with 13 species

This mechanism involves 13 species and is derived from a 17 species mechanism for lean methane-air (flame speed only) based on the GRIMech 2.11. The .cti file is available here. More information can be found on the website of Dr. Tiafeng Lu. In particular, the suitable kinetic routine for this ARC (for a Cantera computation) as well as information about the 17 species skeletal mechanism can be found on the website.

For AVBP users: the kinetic subroutine associated with this mechanism can be found here (format F90), while the simplified transport data can be found on this file (AVBP formatted).


A 22 transported species ARC with NO chemistry (derived with YARC by Thomas Jaravel)

This ARC was developped with YARC based on laminar premixed flames under atmospheric conditions, but it has been shown to work over a broader range of operating conditions. It was derived based on the GRIMech 2.11 mechanism, and it contains a NOx submechanism. It is comprised of 22 transported species, 18 QSS species and 320 reactions. Information about it can be found in Thomas Jaravel's PhD thesis.

The kinetic subroutine associated with this mechanism can be found here (format F90). The simplified transport data can be found on this file (AVBP formatted).


Global mechanisms

The BFER's mechanism

This simplified model uses 6 species for 2 global reactions (fuel oxidation and CO-CO2 equilibrium). The consideration of few reactions and species requires less memory and leads to a very fast computation. This scheme correctly predicts the laminar flame speed on a wide range of fresh gas temperature [(300;700) K], pressure [(1;12) atm] and equivalence ratio [(0.6;1.5)] as well as the burnt gas temperature for an equivalence ratio below 1.4.

More details are provided in this article.


Another 2 step mechanism : 2S_CH4_CM2

This simplified model involves 6 species into 2 global reactions. This mechanism is not good under rich conditions.

1 step mechanism : 1S_CH4_MP1

This simplified model involves 5 species into 1 single global reactions. Adiabatic flame temperatures are not very well predicted. Whenever possible, it is best to use a two step scheme !