[dbxmcf]

Hi, all:

I searched the forum and doxygen, found a function mag and the following comments:
// INSTRUCTION FOR USE!
// When one wants to access the cell centre and magnitude, the
// functionality on the mesh level should be used in preference to the
// functions provided here. They do not rely to the functionality
// implemented here, provide additional checking and are more efficient.
// The cell::centre and cell::mag functions may be removed in the future.

// WARNING! See cell::centre

// first calculate the aproximate cell centre as the average of all
// face centres

I am just confused how to use it and what is the best way to find the cell volume? What I am trying to do is something like:
mesh.cells()[cellLabel].V()...

Thanks a lot!

[eugene]

mesh.V()[cellID]

[nimasam]

hi friend
i want to access volume of cells in volScalarField but in openFoam there is two ways to access to the mesh volume and none of them are volScalarField:
const DimensionedField<scalar, volMesh>& V() const;
or
const scalarField& cellVolumes() const;

[fisch]

nimasam, did you found a solution?
I have the same problem now...

thanks, rupert

[l_r_mcglashan]

mesh.V() is a scalarField, not a volScalarField. Why would you have volumes at patches?

[fisch]

thanks for the quick reply, l_r_mcglashan

i used it without thinking because it's written like this in the programmersGuide P33.

[kaveh19]

hi guys,
how can I measure the volume of geometry in openFoan?

[kmooney]

Originally Posted by kaveh19

hi guys,
how can I measure the volume of geometry in openFoan?

Something like this should work if executed in a top level of a solver:

scalar totalVolume(0.0);
forAll(mesh.cells(),cellI)
{
totalVolume += mesh.V()[cellI];
}

[PicklER]

Is it possible to get the volumes only of the cells at patchID?

If I have:

label patchID = mesh.boundaryMesh().findPatchID(patchName);

Then something like mesh.V()[patchID] ?

Otherwise to get the

cellI

for only the patch corresponding to patchID?

Then I can use that which Kyle recommended. I would like to multiply the value on a patch face with the volume of the cell corresponding to the patch face. The will give me something like a indication of adding mass to cell.

[elmo555]

I also have a question regarding the use of mesh.V():

• Why is a volScalarField not available? Volume is a scalar quantity, and I'd like to have it for each cell in my mesh. How is this related to patches? (@l_r_mcglashan). Patches shouldn't have volumes
• How comes I can use mesh.V() to multiply with a volScalarField, but not divide one by it? Example below...

//works
Info<< "Total liquid volume liquidV = " << sum(mesh.V()*alpha1).value() << endl;
// doesn't work
volScalarField interfDens(aInterfaceCells/mesh.V());

Both alpha1 and aInterfaceCells are volScalarField. What am I doing wrong?

[JackW]

I assume that people want to do it for postprocessing. This is how I did it (by copying LESDelta and cubeRootVolDelta implementation):

# include "calculatedFvPatchFields.H"

volScalarField V (
        IOobject (
            "V",
            runTime.timeName(),
            mesh,
            IOobject::NO_READ
       ),
       mesh,
       dimensionedScalar("small", dimLength*dimLength*dimLength, SMALL),
       calculatedFvPatchScalarField::typeName
);
V.internalField() = mesh.V();
V.write();

The calculatedFvPatchScalarField::typeName just defines calculated patch types, which evaluates to SMALL (what it was initialised as)

[linyanx]

Hi Lennart,
I meet the exactly the same question as you mentioned. I was trying to calculate the weight for every cell and store the value into the volScalarField.

K = 0.5*magSqr(U)*rho*mesh.V();

Sadly the system would complain it while compilation. Do you have any idea about this?
All the best,
Linyan

[saicharan662000@gmail.com]

Hi jack,
I know this post is old but

Can u tell me how to use it in twoPhaseMixtureThermo.C in compressibleInterfoam solver. Because when I am using it as

const volScalarField& cellVolume = mesh.V();
I am getting an error that mesh was not declared in this scope.

[AbhishekTAMU]

I feel that my question is somehow relevant to this thread. Hence, I am posting it here.

I know that magSf() function can calculate individual face area. However, I want to know the surface area of a cell just like we can get cell volume by using mesh.V().

Does anyone know how to get the cell surface area?

Thanks in advance !

[saicharan662000@gmail.com]

Hi abhishek,
Though I didn’t try this. Try using fvc::surfaceSum(mesh.sf())

[AbhishekTAMU]

Hello Hari Charan,

Thanks, I will try it and let you know if it works !

[eduardopaiva]

Someone knows how to do that? I need to get a volume of a cell patch

Originally Posted by PicklER

Is it possible to get the volumes only of the cells at patchID?

If I have:

label patchID = mesh.boundaryMesh().findPatchID(patchName);

Then something like mesh.V()[patchID] ?

Otherwise to get the

cellI

for only the patch corresponding to patchID?

Then I can use that which Kyle recommended. I would like to multiply the value on a patch face with the volume of the cell corresponding to the patch face. The will give me something like a indication of adding mass to cell.