The C2_NOx mechanism was developed at Ansys. This reaction mechanism, consisting of gas-phase chemistry, thermodynamic, and transport data files, is provided in the system data folder. It describes the oxidation of hydrogen, methane, and ethane over a broad range of temperature and pressure and includes NOx chemistry.
The mechanism is based on a published mechanism for oxidation of model-fuel components [3]. Many reactions in the base mechanism have been updated based on most recent kinetic studies. Reaction sub-mechanisms have been updated based on recent studies on hydrogen [4] and methane [5] oxidation. The chemically activated reaction of ethyl radical with molecular oxygen has also been updated based on Naik and Dean [6]. The base high-temperature NOx chemistry is from the GRI-mech 3.0 mechanism (see GRImech 3.0). Recently, researchers have identified the mutual sensitization effect of NOx on hydrocarbon oxidation at lower temperatures. The current mechanism includes the most recent pressure-dependent NOx -hydrocarbon reactions from Rasmussen [7]. Reactions pertaining to NOx chemistry in the intermediate temperature region has also been updated based on the review of Dagaut, Glarborg et al. [8].
The final pressure-dependent mechanism contains 99 chemical species and 693 elementary reactions that describe hydrocarbon oxidation chemistry as well as NOx chemistry over broad range of temperatures and pressures. Most of the reactions are reversible and many of the reactions have explicit descriptions of their pressure-dependencies, using the TROE and PLOG formulation and including enhanced collision efficiencies for particular species.