[NorthCFD]

Hello,

I am trying to change the value of a variable in updateFields.H inside solver folder for a purpose.

Problem is when I try to print the values of this variable in boundary condition file (in p) to check ıf it is correct, it prints all zero meaning I failed.

What may be the problem ?

createFields:

volScalarField checkVol
(
    IOobject
    (
        "checkVol",
        runTime.timeName(),
        mesh,
  	IOobject::NO_READ,
	IOobject::AUTO_WRITE
    ),
    mesh,
    dimensionedScalar("checkVol", dimless, 0.0 )
);

updateFields:

  forAll(checkVol, facei) {
    checkVol[facei] = 250;
  }

boundary condition:

    const fvPatchField<scalar>& checkVol=
        patch().lookupPatchField<volScalarField, scalar>("checkVol");

    forAll(checkVol, checki) {

      Info << "checkVol: " << checkVol[checki] << endl;
    }

I added every line with checkVol, sorry couldn't include whole code.

Any help is appreciated.

[olesen]

Your choice of variable names is a bit misleading. If you write this:

 forAll(checkVol, celli)
{
    checkVol[celli] = 250;

}

It is at least clear that you are only touching the volume values. The boundary patch values can either be something that you are prescribing yourself (eg, inlet, wall, etc) or simply a "calculated" or zeroGradient value. You need to ensure that all of those types of patches know about which changes you just made to the volume (internal field) values:

checkVol.correctBoundaryCondtions();

Let us know how you get on with that.

[NorthCFD]

Thanks for the response Olesen.

Sorry that I gave a hard to understand code, this was because, I tried to give a template of what I am doing since there are few more things with similar variables and I had restrictions.

To answer you, checkVol is a not a boundary value itself like p or U but a intermediate step for calculating U and p, think it like phi or gamma. checkVol value is calculated inside another updateCheck.h file just before updateFields.H. So no need to call correctBoudnaryCondition function.

The problem is after it is calculated and assigned in that updateCheck.h file as previously mentioned, its values can be printed out. But when trying to print its values inside p boundary condition, it gives all zeros for it.

[NorthCFD]

UPDATE !!!

I was using lookupPatchField to retrieve checkVol which was giving me zeros, I changed inital to 225 instead. Then it started to print out 225s instead of zeros. This concluded that it was just giving initial values and no other intermediate processes were done (unless some other function that turns the values to initials but seems unlikely).

Then I tried to use the lookupObject to retrieve whole field instead of that single patch. This way it gave me 250 like it was supposed to (as I was changing values to 250 in updateFields, just arbitary value).

From now on I can use these values and my problem is fixed for now. BUT this raises new questions to me.
-Why did lookupObject worked as intended but lookupPatchField not?
-Isn't lookupPatchField is similar to lookupObject but the difference is it just gives the values on these patches instead of whole domain?

Thanks.

[olesen]

You concluded that you do not need to call correctBoundaryConditions() despite my attempt to describe why it is necessary and what it does.
For what it's worth, I think that I have a somewhat better than basic knowledge of OpenFOAM and that my suggestion may have some merit.

[NorthCFD]

It was inappropriate to not try what you said and just continue, after asking a question here. I understand and am sorry about that.

I changed part of my code back and tried what you said. Added checkVol.correctBoundaryCondition() inside updateFields. And it doesn't work.

My code is not well written in "OpenFOAM way", probably that is the issue.