[metalfox]

I noticed that in the combustion models inheriting from

singleStepCombustion

assign the fuel consumption rate

wFuel_

with the equality operator == instead of the assignment operator.

Does anybody know why?

For example, in infinitelyFastChemistry.C (https://develop.openfoam.com/Develop...hemistry.C#L67) we have:

template<class ReactionThermo, class ThermoType>
void infinitelyFastChemistry<ReactionThermo, ThermoType>::correct()
{
    this->wFuel_ == dimensionedScalar(dimMass/dimVolume/dimTime, Zero);

    if (this->active())
    {
        this->singleMixturePtr_->fresCorrect();

        const label fuelI = this->singleMixturePtr_->fuelIndex();

        const volScalarField& YFuel =
            this->thermo().composition().Y()[fuelI];

        const dimensionedScalar s = this->singleMixturePtr_->s();

        if (this->thermo().composition().contains("O2"))
        {
            const volScalarField& YO2 = this->thermo().composition().Y("O2");

            this->wFuel_ ==
                this->rho()/(this->mesh().time().deltaT()*C_)
               *min(YFuel, YO2/s.value());
        }
    }
}

[s1291]

take a look at this post:
Difference between = and ==