[hauschildt03]

In $FOAM_SRC/regionModels/pyrolysisModels/reactingOneDim/reactingOneDim.C, there is the following function:

void reactingOneDim::updateFields()
{
    if (qrHSource_)
    {
        updateqr();
    }

    //Note: Commented out as the sensible gas energy is included in energy eq.
    //updatePhiGas();
}

Because "//updatePhiGas();" is commented out, the field phiGas remains at its initial value.

As a consequence, for example in the combustion/fireFoam/LES/oppositeBurningPanels tutorial, there is no convective transport from the pyrolysis regions to region0. In this tutorial, the field 0/U contains:

    "(region0_to.*)"
    {
        type            mappedFlowRate;
        nbrPhi          phiGas;
        value           uniform (0 0 0);
    }

But phiGas is never updated.

Which OpenFoam version is recommended to work with fireFoam?

[ashish.vinayak]

You need to uncomment updatePhiGas() since that is responsible for computing the gas release at the face.
If you don't want to use the enthalpy computation from updatePhiGas, you can comment that out instead within the function.