[Zhiheng Wang]

Hi,
I want to calculate the species diffusivity D (fick law) on basis of binary diffusivity I am knowing the formulation ,
My problem is how to extract the data.

As in creatFields.H spicies defined as
basicMultiComponentMixture& composition = thermo.composition();
PtrList<volScalarField>& Y = composition.Y();

every property kappa, mu, alpha,or rho for example is called as composition.rho(i,1e5,T)

How can I implement D (molecular diffusion in same form).

Or if any one suggest how to create PtrList<volScalrField>& D = some variable which can calculate this.

[Zhiheng Wang]

No body ????

[freuen]

For Openfoam 3.0, You can put this code in the createFields.H

PtrList<volScalarField>& Y = composition.Y();
PtrList<volScalarField> Diff;
forAll(Y, i)
{
word name("Diff_" + Y[i].name());
Diff.append(new volScalarField
(
IOobject
(
name,
runTime.timeName(),
mesh,
IOobject::NO_READ,
IOobject::AUTO_WRITE
),
mesh,
dimensionedScalar(name, dimensionSet(0,2,-1,0,0,0,0), 0)
)
);
fields.add(Diff[i]);
}

Originally Posted by Zhiheng Wang

Hi,
I want to calculate the species diffusivity D (fick law) on basis of binary diffusivity I am knowing the formulation ,
My problem is how to extract the data.

As in creatFields.H spicies defined as
basicMultiComponentMixture& composition = thermo.composition();
PtrList<volScalarField>& Y = composition.Y();

every property kappa, mu, alpha,or rho for example is called as composition.rho(i,1e5,T)

How can I implement D (molecular diffusion in same form).

Or if any one suggest how to create PtrList<volScalrField>& D = some variable which can calculate this.

[atulkjoy]

HI,
Sir Can you answer why line number 174 and 175 are commented in file. These are meant to be up-dation of species diffusivity with sutherland model.

It is about same thing but here the Diffusivity is varing with temperature.

https://github.com/OpenFOAM/OpenFOAM...andTransport.H

175 // Species diffusivity //inline scalar D(const scalar p, const scalar T) const;

[freuen]

I guess it's reserved for future development


Sent from my iPhone using CFD Online Forum mobile app

[SH_Zhong]

Originally Posted by freuen

For Openfoam 3.0, You can put this code in the createFields.H

PtrList<volScalarField>& Y = composition.Y();
PtrList<volScalarField> Diff;
forAll(Y, i)
{
word name("Diff_" + Y[i].name());
Diff.append(new volScalarField
(
IOobject
(
name,
runTime.timeName(),
mesh,
IOobject::NO_READ,
IOobject::AUTO_WRITE
),
mesh,
dimensionedScalar(name, dimensionSet(0,2,-1,0,0,0,0), 0)
)
);
fields.add(Diff[i]);
}

Hi,
I write the code into my creatFields.H,
but I get this error.

'fields' was not declared in this scope.
fields.add(Diff[i]);

So what can I do to get rid of the problems, many thanks in advance!

[atulkjoy]

Hi use the code I have sent you you would be able to find Diffusivity. use 2.3.x firefoam as solver. Copy $WM_PROJECT_DIR/fireFoam to $WM_PROJECT_USER_DIR/myfirefoam.
2. Rename createFields.H to old.createFields.H and download createFields.H I sent to you.
3. Add starting lines of sutherland.C to fireFoam.c rename it as MyfireFoam.
4. change make/file, edit this file from fireFoam.C to myFireFoam.C and $FOAM_APPBIN/fireFoam to $FOAM_USER_APPBIN/MyfireFoam.
compile and run the case with declaration of speciesdict file in constantFolder.