[mdjames]

Hi all,

This seems like it could be really easy for some of you here... However, it evades me.

I'm trying to declare a scalar field, I'll call it "j", within dynSmagorinsky.C

I'd like to solve a transport equation for j, so i just need some way to define initial and boundary conditions. The rest of the code seems to compile fine...just not this seemingly mundane detail.

I tried letting an H file open it up but it seems to complain about not knowing anything about the mesh, which i suppose makes sense to me. Correcting that problem was leading me down a dark and winding path. I thought surely there's an elegant way.

Can anyone help me out here?

Thanks a lot!

[nakul]

Hi,

All such changes to field are made when they are defined in createFields.H

Define your scalar field in this file just the way p or T are defined and everything should work fine.

[mdjames]

Nakul,

Thank you very much for your reply.

I would agree, and have done this when adding a field to solver. However, the fields in the dynSmagorinsky model code are generated within the code, since they are derived from the U and k fields. The problem thus arises in establishing a new field within the code. In short, there is no createFields.H included in dynSmagorinsky.C . Also, I tried to include a new H file to accomplish what createFields.H does in a solver, but to no avail.

dynSmagorinsky.C includes dynSmagorinsky.H, which appears to collect the U, phi and k fields from somewhere (eventually the solver?). So, it seems I should be similarly declaring my new volScalarField here.

Any thoughts?

[tonyuprm]

Hi Matt,

I'm not sure how to do a scalar field, but this is how you can do a volVectorField:


volVectorField j
(
IOobject
(
"j",
U.time().constant(),
U.mesh(),
IOobject::NO_READ,
IOobject::AUTO_WRITE
),
U.mesh(),
dimensionedVector("j",dimForce/dimVolume/dimDensity,vector::zero)
);

Hope this helps you out.

Tony

[nakul]

Hi

I don't have this model in my version of OF so if you could just upload the source code of this solver and point out your problem, I'll have a look.

[Davidlt]

Hi Matt & everyone

I was wondering if you have succeeded on what you're looking for. I'm also interested to add a new scalarfield in a sgs model which is computed by the solver and refreshed for each time step. So if you have any thoughts...

Thx

[morard]

Hi everyone.

Matt and David, I hope that you are succeeded up to now, but if you are not,
this is the way how I did it.

In .H file of your model I just added a new function:

dimensionedScalar c1(const volSymmTensorField& D) const;

and then in .C

dimensionedScalar nameOfYourModel::c1(const volSymmTensorField& D) const
{
.... some code
}

At each time step I calculate c1, use this value to calculate some other variables
which are later used for temperature equation...

Maybe you can use something similar to this...

[Davidlt]

Thank you for the answer.

But unfortunately, the scalarfield needed is computed by the solver and not in the sgs library itself. So I concluded that I need to modify LESModel.H and GenEddyVisc.H to transfer the information between the solver and the libraries used.

I'll try this.

David

[morard]

No problem, it is straightforward.
First you have to add scalar field to turbulenceModel (add new variable, change constructor,...), then adjust LESModel, GenEddyVisc and finally your own model.
Maybe also something else but I cannot remember at the moment.

Just copy the whole folder (incompressible or compressible), change name, and
inside you can do whatever you want...

Dejan