[chrisb2244]

Hi,

I'm writing a class to create and recreate an alpha1 field.
It's (sort of, at least) working for internal cells, but the boundary fields are a bit of a problem.

Currently, I have:

Foam::volScalarField Foam::regenerateAlphaClass::regenerateAlpha()
{
	if (1) Pout<< "Calling regenerateAlphaClass::regenerateAlpha()" << endl;
	// Going to set values of the data points in a constructor.
	// A separate function can calculate the expected heights.
	// This only (?) needs to work out which cells should be given which values,
	// and write an alpha1 file.
	
	volScalarField alpha1
	(
		IOobject
		(
			"alpha1",
			mesh_.time().timeName(),
			mesh_,
			IOobject::NO_READ,
			IOobject::AUTO_WRITE,
			true // registery
		),
		mesh_,
		dimensionedScalar
		(
			"alpha1",
			dimensionSet(0, 0, 0, 0, 0, 0, 0),
			0.0
		)
	);

	double yMid;
	yMid = 0.6; // set this using the dictionary? Or some sort of IO operation.
	double yHeight = yMid;
	forAll(mesh_.cellCentres(), i)
	{
		double cellHeight = sqrt(mesh_.cellVolumes()[i] / cellDepth_);
		//~ Pout<< "cellHeight = " << cellHeight << endl;
		yHeight = yMid;
		Foam::vector position(mesh_.cellCentres()[i]);
		for (unsigned int k=0; k < cosineVector.size(); k++)
		{
			yHeight += cosineVector[k](position[0]);
		}
		double deltaY = yHeight - position[1];
		if (deltaY < -cellHeight)
		{
			alpha1.internalField()[i] = 1.0;
		}
		else if (deltaY > cellHeight)
		{
			alpha1.internalField()[i] = 0.0;
		}
		else
		{
			double value_Alpha = (0.5+(-0.5 * (deltaY/cellHeight)));
			alpha1.internalField()[i] = value_Alpha;
		}
	}
	forAll(alpha1.boundaryField()[0], faceI)//side left?
	{
		alpha1.boundaryField()[0][faceI] = alpha1.internalField()[mesh_.owner()[faceI]];
	}
	forAll(alpha1.boundaryField()[1], faceI)//side right
	{
		Pout<< "Right: intField = " << alpha1.internalField()[mesh_.owner()[faceI]] << endl;
		alpha1.boundaryField()[1][faceI] = alpha1.internalField()[mesh_.owner()[faceI]];
	}
	forAll(alpha1.boundaryField()[2], faceI) //bottom
	{
		alpha1.boundaryField()[2][faceI] = 0;
	}
	forAll(alpha1.boundaryField()[3], faceI)//top
	{
		alpha1.boundaryField()[3][faceI] = 1;
	}
	
	
	forAll(alpha1.boundaryField(), i)
	{
		Pout<< "name of bF()[i]? (types) = " << alpha1.boundaryField().types() << endl;
		Pout<< "boundaryField()[i] = " << alpha1.boundaryField()[i] << endl;
		
	}
	return alpha1;
}

The internal cells, like I said, are being given values which (at least to first glance) seem sensible, but the boundary cells are being set to 0 for the alpha1.internalField() calls (even though in the top half, they should be =1, etc).

Firstly, can I change this from setting boundaryField()[0, 1, 2, 3] to something like boundaryField()[name of patch?] or alternatively

forAll(alpha1.boundaryField(), fieldI)
{
    if (alpha1.boundaryField()[fieldI].name() == top)
    // set to top conditions, etc
}

The patchIdentifier class looks like it might be helpful for that, but looking at the Doxygen information I can't see how I would construct a meaningful patchIdentifier object (and assuming I therefore need already existing patchIdentifier objects, I can't work out how to get references to them).

My second problem relates to the values of internalField being set to 0 in the boundaryField section, but I expect this might be related to a mislabelling of faceI? If someone could confirm this, that'd be great!

A much preferable solution would be if I could find the patch (by name?) and then set it's condition (currently all to calculated) to, for example, zeroGradient, or fixedValue (0), or whatever.

Any help would be much appreciated,

Christian

[chrisb2244]

Simple solution (at least for all one type of boundary except the one set to empty)

use:

volScalarField alpha1
	(
		IOobject
		(
			"alpha1",
			mesh_.time().timeName(),
			mesh_,
			IOobject::NO_READ,
			IOobject::AUTO_WRITE,
			true // registery
		),
		mesh_,
		dimensionedScalar
		(
			"alpha1",
			dimensionSet(0, 0, 0, 0, 0, 0, 0),
			0.0
		),
		zeroGradientFvPatchField<scalar>::typeName
	);

To find the patches more reliably (independent of order of input now) (although I don't need this anymore)

label topID = mesh_.boundaryMesh().findPatchID("top");

etc.

[chrisb2244]

Derp - the doxygen information also lists a constructor with a wordList for 'wantedTypes'

Constructor can be written something like:

        wordList wantedTypes;
	wantedTypes.append(cyclicPolyPatch::typeName);
	wantedTypes.append(cyclicPolyPatch::typeName);
	wantedTypes.append(zeroGradientFvPatchField<scalar>::typeName);
	wantedTypes.append(zeroGradientFvPatchField<scalar>::typeName);
	wantedTypes.append(emptyPolyPatch::typeName);
	
	volScalarField alpha1
	(
		IOobject
		(
			"alpha1",
			mesh_.time().timeName(),
			mesh_,
			IOobject::NO_READ,
			IOobject::AUTO_WRITE,
			true // registery
		),
		mesh_,
		dimensionedScalar
		(
			"alpha1",
			dimensionSet(0, 0, 0, 0, 0, 0, 0),
			0.0
		),
		wantedTypes
	);