[c_dowd]

Hi all
I have a feeling there is a very obvious solution to this, but I can't seem to find it for the life of me, i must not be searching for the right thing. I'm adding a new dimensionless scalar into the buoyantPimpleFoam solver, which uses a generic scalar transport equation. I've added it as a volScalarField just as shown in the examples here and here. In particular, the transport equation is:

{
fvScalarMatrix zfEqn
(
fvm::ddt(zf)
+ fvm::div(phi, zf)
- fvm::laplacian(alphaz, zf)
);
zfEqn.solve();
}

The issue is that every time I try to run the solver, I get an error saying that the dimensions don't agree (in particular the first section where [0 0 -1 0 0 0 0] + [1 -3 -1 0 0 0 0], i can change the dimensions of alphaz to make the second bit work no problems). I can clearly see that they don't, yet I can't work out how to make sure that they do. I can't just change the dimensions of zf as it is used in other equations where it is important that it is dimensionless. I tried adding another scalar variable to make phi dimensionless, but I kept having issues implementing it and thought there had to be a better way.

[Horus]

You can turn off dimensions checking though it is not recommended. Set in your controlDict:

dimensionSet 0;

[c_dowd]

Ah thanks a lot. In fact I ended up just putting a new constant in the ddt part to make the dimensions equal but that's good to know.

[Bernhard]

Originally Posted by c_dowd

Ah thanks a lot. In fact I ended up just putting a new constant in the ddt part to make the dimensions equal but that's good to know.

The dimension of alphaz should be m^2/s, because it is a diffusion parameter.

[Action.Kamen]

Originally Posted by Horus

You can turn off dimensions checking though it is not recommended. Set in your controlDict:

dimensionSet 0;

I was using OpenFOAM v1912 and dimensionSet 0; was not working so a quick update
this works for now(to turn off dimension checking)


DebugSwitches
{
dimensionSet 0;
}


Add above in the controlDict