[Tibo99]

Hi foamers,

I try to fix the value of U at the first cell of the domain (from the wall) via the fvOptions framework by using the function ''vectorCodedSource'.

I don't know what I'm doing wrong. The turbulence model compute and I don't get any message of error whatsoever.

But, when I look at the result during the couple of first iteration, the value of U at the specify cell is not what I fixed.

I used the 'topoSetDict' in order to make a selection of the cells that I want to apply the condition on.

To put you in context, in order to simplify the problem, I applied the fix value at the first cell center to a 1D simulation first (the domain is x=1mm, y=150mm(dy=1mm), z=1mm) and then, it will extend to a 2D simulation after. The value of U will be determine by a formula later on.

If you guys have suggestions, let me know. It would be really appreciated!

Here are the code:

topoSetDict:

actions
(
    // U firstCellFix
    {
        name    firstCellFixU;
        type    cellSet;
        action  new;
        source  boxToCell;
        box     (0 0 0) (0.001 0.001 0.001);
    }
    {
        name    firstCellU;
        type    cellZoneSet;
        action  new;
        source  setToCellZone;
        set     firstCellFixU;
    }

);

fvOptions files:

fixU
{
    type				vectorCodedSource;
    active				true;
    selectionMode                       cellSet;
    cellSet				firstCellU;
    fields				(U);
    name				Ufix;
    
    codeSetValue
    #{
    
			cellSet selectedCells(mesh_, cellSetName_);
			labelList cells = selectedCells.toc();
			vectorField values(cells.size());
			
			
		forAll(cells, i)
		{	
			values[i].x() = 1.458;
			values[i].y() = 0.0;
			values[i].z() = 0.0;
		};			
    
		eqn.setValues(cells, values);
		
    #};    

}

Thank you very much for your helps!

[Michael@UW]

Dear René,
Did you solve the problem? I tried to fix the velocity at some specific cells but failed. It seems the velocity is changed by setValues(cells, values), but it is not the value as specified. If you have figured out the issue, could you please share your solution?

Kind regards,
Michael

[Tibo99]

I was able to make it work, but maybe its not the way you looking for.

Hope this will help you.

topoSetDict:

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v1906                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      topoSetDict;
}

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

actions
(
    // U firstCellFix
    {
        name    firstCellFixU;
        type    cellSet;
        action  new;
        source  boxToCell;
        box     (0 0 0) (0.001 0.001 0.001);
    }
    {
        name    firstCellU;
        type    cellZoneSet;
        action  new;
        source  setToCellZone;
        set     firstCellFixU;
    }

);

// ************************************************************************* //

fvOptions:

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v1906                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    location    "system";
    object      fvOptions;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

fixU
{
	type				vectorFixedValueConstraint;
	active				true;    
	
	selectionMode		cellZone;
	cellZone			firstCellU;	
    volumeMode			absolute;
    
    fieldValues
	{
		U	(5.1053110026 0 0);
	}
}

// ************************************************************************* //