[weikou]

Hi,



I am aiming to write a chemistry-solver (I am still with OpenFoam v4.1) , that is solving the reaction and scalar transport on a (RANS averaged turbulent) incompressible flow field, that is already in steady state.

Therefore I need to solve the YEqn only, but adjust it by giving it a reaction source term.

Since I am working with incompressible flow, the dimensions of the terms are all in s⁻¹.

But dimension of reaction->R(Yi) is in kgm⁻³s⁻¹.



Therefore I would like to calculate


volScalarField& reactionRate = (reaction->R(Yi)) / rhoRef;


with 'rhoRef' being a scalar with dimensions kgm⁻³ to end up with reactionRate in dimension s⁻¹.

But when I try, it doesn't compile and gives me the error


no match for ‘operator/’ (operand types are ‘Foam::tmp<Foam::fvMatrix<double> >’ and ‘Foam::dimensionedScalar {aka Foam::dimensioned<double>}’)

Because I didn't find a lot of information on this in the OpenFOAM programmers' guide, I naively thought, this should work, but it seems like I was wrong. Maybe you have an idea, on how to fix this?


Thanks already in advance!
Wiebke

[Tobi]

The problem you encounter here is that the ::R() function will not return a volScalarField but it will rather be a fvScalarMatrix and for the fvScalarMatrix we don´t have the operator/ defined. Out of the box, I am not sure about the conversions implemented. However, I don´t think that even this line will work:

volScalarField& reactionRate = reaction->R(Yi)

[weikou]

Hi Tobias,



thanks for the quick answer. In that case, it is probably best to leave the result of ::R() as it is and multiply all the other fields in the equation with a constant density.



I just tried it and that seems to work. Thanks for clarifying the types there.



Wiebke

[Tobi]

A work around could be to make it in that way:

fvScalarMatrix reactionRates = reaction->R();

fvScalarMatrix tmp(reactionRates.size(), dimensionSet("tmp", dimensions(Your Dimensions), scalar(0));    // Not sure about the constructor of that class right now


// Create loop and copy only the data without the units into the new one.