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Combustion of n-heptane (Ordinary differential equations)

Case directory

$FOAM_TUTORIALS/combustion/chemFoam/nc7h16

Summary

We import CHEMKIN II input files and calculate chemical reaction, then compare the calculation result with CHEMKIN II's result. CHEMKIN is a proprietary software for chemical reaction calculations that is developed at Sandia National Laboratories.

We solves pressure, temperature, and chemical composition, but not flow. And there are no spatial degrees of freedom (i.e. we calculate reactions in a single cell as ordinary differential equations). There are CHEMKIN format input files in the directory "chemkin", and we load them from the file "thermophysicalProperties" in the directory "constant" as follows.

thermoType
{
    type            hePsiThermo;
    mixture         reactingMixture;
    transport       sutherland;
    thermo          janaf;
    energy          sensibleEnthalpy;
    equationOfState perfectGas;
    specie          specie;
}

CHEMKINFile     "$FOAM_CASE/chemkin/chem.inp";
CHEMKINThermoFile "$FOAM_CASE/chemkin/therm.dat";
CHEMKINTransportFile "$FOAM_CASE/chemkin/transportProperties";

The initial pressure, temperature, and chemical composition are defined in the file "initialConditions" in the directory "constant" as follows. The entire calculation takes into account 544 chemical species and 2446 chemical reactions defined in the file "chemkin/chem.inp".

constantProperty pressure;

fractionBasis   mole;
fractions
{
    NC7H16      0.090909;
    N2              3.76;
    O2              1;
}
p               5.06625e+06;
T               800;

And the file "chemistryProperties" in the directory "constant" is used to configure the chemistry solver.

The calculation result is as follows.

Comparison of temperature calculation results between OpenFOAM (chemFOAM) and CHEMKIN II