[TurbJet]

Hello to everyone,

Currently I am using MPPICFoam to track particles. Now I have to modify one of its source files, which needs to access the information like mesh and other user-created fields. So how am I gonna do that? How am I gonna access other information outside the source file, in this case mesh, user-created fields? Should I include some headers for the mesh or something else? I tried to include headers like "polyMesh.H" "fvCFD.H", but it did not work out.

I am kind of desperate now. Hope there is someone could help me out here.

Thanks a lot.


PS:
to be more specific. I am doing Lagrangian Particle tracking and using MPPICFoam. Currently I am trying to make some modification to the file Cloud.C. What I am trying to do is to loop over all the mesh and particles, and then check the mesh where the particle is at, see how is the porosity of this mesh; if the porosity of this mesh is 0, delete the particle, otherwise, do nothing.


the codes I add:

forAll(mesh.C(), celli)
{
if (( abs(mesh().C()[celli].x() - p.position().x()) < posdiff )
&&( abs(mesh().C()[celli].y() - p.position().y()) < posdiff ))
{
if (abs(porosity[celli]) <= threshold)
{
deleteParticle(p);
}
}
}

where posdiff and threshold are just constants I defined, and porosity is a new field I create; deleteParticle is a member function of Cloud.C; p.position() is to access the coordinates of the particles.


when I compile the codes, the compiler gives:

/opt/openfoam4/src/lagrangian/basic/lnInclude/Cloud.C: In member function ‘void Foam::Cloud<ParticleType>::move(TrackData&, Foam::scalar)’:
/opt/openfoam4/src/lagrangian/basic/lnInclude/Cloud.C:309:13: error: ‘mesh’ was not declared in this scope
forAll(mesh.C(), celli)
^
/opt/openfoam4/src/OpenFOAM/lnInclude/UList.H:430:30: note: in definition of macro ‘forAll’
for (Foam::label i=0; i<(list).size(); i++)

UPDATE:

I figured out the mesh problem (for those who might be interested, see my reply below at #6). And I was inspired by this thread:
const volVectorField& U = db().lookupObject<volVectorField>("U") gives runtime error

But I am still not able to access my self-created field "porosity" within this scope, i.e., within this Cloud.C file.

I create the porosity field by add codes in createFields.H, and write another header file to compute the field. Then I include this header file at the beginning of the solver MPPICFoam.

The compiler says the same thing:

error: ‘porosity’ was not declared in this scope
if (abs(porosity[celli]) <= threshold)

Anyway, to narrow this down: how am I gonna retrieve self-created field within other source file?

Any thoughts, guys?

[TurbJet]

could someone please answer my question? I am desperate

[TurbJet]

anyone can help me out?

[Taataa]

You need to be more specific about your problem if you want help.

Regarding the mesh not declared error you need use it like this:
mesh().C()
in the newer versions of OF.

[TurbJet]

Originally Posted by Taataa

You need to be more specific about your problem if you want help.

Regarding the mesh not declared error you need use it like this:
mesh().C()
in the newer versions of OF.

the compiler gives

/opt/openfoam4/src/lagrangian/basic/lnInclude/Cloud.C: In member function ‘void Foam::Cloud<ParticleType>::move(TrackData&, Foam::scalar)’:
/opt/openfoam4/src/lagrangian/basic/lnInclude/Cloud.C:309:13: error: ‘mesh’ was not declared in this scope
forAll(mesh.C(), celli)
^
/opt/openfoam4/src/OpenFOAM/lnInclude/UList.H:430:30: note: in definition of macro ‘forAll’
for (Foam::label i=0; i<(list).size(); i++)

I am doing Lagrangian Particle tracking and using MPPICFoam. Currently I am trying to make some modification to the file Cloud.C; the goal I want to achieve is that I want to access the mesh center coordinates to compare with the coordinates of particles.

the codes I add:

forAll(mesh.C(), celli)
{
if (( abs(mesh().C()[celli].x() - p.position().x()) < posdiff )
&&( abs(mesh().C()[celli].y() - p.position().y()) < posdiff ))
{
if (abs(porosity[celli]) <= threshold)
{
deleteParticle(p);
}
}
}

where posdiff and threshold are just constants I defined, and porosity is a new field I create; deleteParticle is a member function of Cloud.C; p.position() is to access the coordinates of the particles.

I am not sure, but I think the fvMesh info is just not available within this scope, even if I include the header file "fvMesh.H" into this .C file. And I tried to add the brackets after "mesh" as you suggested, but it still not work.

Now I am thinking about passing mesh as an argument into the member function of Cloud.C, but that needs to modify a chunk of other functions.

So I am running out of thoughts.

[TurbJet]

I kind of figured out this mesh problem.

I added few sentences in the code:

const objectRegistry& db();
const volVectorField& U = db().lookupObject<volVectorField>("U");
const fvMesh & mesh = U.mesh();

and the compiling worked out without further warning, even though I am not sure if the codes as a whole would work.

But the remaining question is: how am I gonna make the self-created field "porosity" to be accessible within this context? The compiler says the same thing:

error: ‘porosity’ was not declared in this scope
if (abs(porosity[celli]) <= threshold)

[TurbJet]

following the previous procedure, I tried the following:

const volScalarField& porosity = db().lookupObject<volScalarField>("porosity");

to include my self-created scalar field "porosity". However, the compiler said:

Make/linux64GccDPInt32Opt/modDPMFoam.o: In function `_GLOBAL__sub_I_modDPMFoam.C':
modDPMFoam.C: (.text.startup+0x73) : undefined reference to `db()'
modDPMFoam.C: (.text.startup+0xc5) : undefined reference to `db()'
collect2: error: ld returned 1 exit status
make: *** [/home/ipalab/OpenFOAM/ipalab-4.1/platforms/linux64GccDPInt32Opt/bin/modDPMFoam] Error 1

Seems it has some linking issue. Does anyone know what's wrong with it? Any thoughts?

[Taataa]

This is the way that I would declare velocity and cell centers:

const volVectorField& U =  mesh().lookupObject<volVectorField>("U");
const volVectorField& centers = mesh().C();

Regarding the dictionary, here is an example for finding air density in transportProperties:

const objectRegistry& db = mesh().thisDb();
const dictionary& transportProperties =
    db.lookupObject<IOdictionary>
    (
        "transportProperties"
    );

dictionary alpha2
    (
        transportProperties.subDict("air")
    );
        
dimensionedScalar rhoAir
    (
        "rhoAir",
        dimDensity,
        alpha2.lookup("rho")
    );

You can adjust it based on the dictionary and sub-dictionaries.

[TurbJet]

Originally Posted by Taataa

This is the way that I would declare velocity and cell centers:

const volVectorField& U =  mesh().lookupObject<volVectorField>("U");
const volVectorField& centers = mesh().C();

Regarding the dictionary, here is an example for finding air density in transportProperties:

const objectRegistry& db = mesh().thisDb();
const dictionary& transportProperties =
    db.lookupObject<IOdictionary>
    (
        "transportProperties"
    );

dictionary alpha2
    (
        transportProperties.subDict("air")
    );
        
dimensionedScalar rhoAir
    (
        "rhoAir",
        dimDensity,
        alpha2.lookup("rho")
    );

You can adjust it based on the dictionary and sub-dictionaries.

actually, I was trying to declare mesh, not velocity.

[TurbJet]

Originally Posted by Taataa

This is the way that I would declare velocity and cell centers:

const volVectorField& U =  mesh().lookupObject<volVectorField>("U");
const volVectorField& centers = mesh().C();

Regarding the dictionary, here is an example for finding air density in transportProperties:

const objectRegistry& db = mesh().thisDb();
const dictionary& transportProperties =
    db.lookupObject<IOdictionary>
    (
        "transportProperties"
    );

dictionary alpha2
    (
        transportProperties.subDict("air")
    );
        
dimensionedScalar rhoAir
    (
        "rhoAir",
        dimDensity,
        alpha2.lookup("rho")
    );

You can adjust it based on the dictionary and sub-dictionaries.

Basically, I did this:

const objectRegistry& db();
const volVectorField& U = db().lookupObject<volVectorField>("U");
const fvMesh & mesh = U.mesh();

const volScalarField& porosity = db().lookupObject<volScalarField>("porosity");

IOdictionary porosity
(
IOobject
(
"porosity",
this->db().time().constant(),
this->db(),
IOobject::READ_IF_PRESENT,
IOobject::NO_WRITE
)
);

The declaration of U and mesh were a success, but the declare of the self-created field "porosity" was not.

[tooran]

I created a new viscosity model base on HerschelBulkley model . I want to model the following structure:
If y< 0.048
Then return...
Else return....
I am trying to access the points in the mesh inside the the HerschelBulkley class.So I added the following loop on the calcNu() function in HerschelBulkley :
forAll (etat, cellI)
{
etat[cellI]=mrsh.c()[cellI].y();
If (etat[cellI]<0.048)
{....
But When I compiled the error appeared :
"mesh is not declare in this scope"
I solved this error by adding the following lines:
const objectRegistry& db();
const volVectorField& U = db().lookupObject<volVectorField>("U");
const fvMesh & mesh = U.mesh();
forAll (etat, cellI)
{
etat[cellI]=mrsh.c()[cellI].y();
If (etat[cellI]<0.048)
{....
Now the libary compiles with out errors,but when I want to run the case with the solver simple foam , the following error appears:
Undefined symbol: _ZN4Foam15viscosityModels2dev
Could anyone help me?
Thanks

[saicharan662000@gmail.com]

Hello TurbJet,
I had the same problem can you go through my post . I am sharing the link below.
request for a field in object registry failed


Thanks in advance.