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Convection–diffusion equation solver

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Old   November 24, 2010, 16:24
Default Convection–diffusion equation solver
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Daniele
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Hi
I would create my solver for convectio-diffusion equation:

Where v field is know. Where should I star to solve this problem? How can I create OpenFoam code? I would use simpleFoam to calculate U field and join simpleFoam solver with my solver to have only one solver to calculate scalar field c.
Thanks


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Old   November 25, 2010, 05:25
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Anton Kidess
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Your problem is pretty much equivalent to this one: http://openfoamwiki.net/index.php/Ho...ure_to_icoFoam. Just instead of adding the equation to icoFoam, do so with simpleFoam.
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Old   November 25, 2010, 06:40
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Thanks
Perfect, but in simpleFoam (or pisoFoam) where I add this line:

dimensionedScalar nu ( transportProperties.lookup("nu") );

for my scalar transport properties?
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Old   November 25, 2010, 09:54
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I would add the following code to createFields.H:

Code:
Info<< "Reading transportProperties\n" << endl;

IOdictionary transportProperties
(
    IOobject
    (
        "transportProperties",
        runTime.constant(),
        mesh,
        IOobject::MUST_READ,
        IOobject::NO_WRITE
    )
);

dimensionedScalar DC
(
     transportProperties.lookup("DC")
);

Info<< "Reading field C\n" <<endl;
volScalarField C
(
    IOobject
    (
         "C",
         runTime.timeName(),
         mesh,
         IOobject::MUST_READ,
         IOobject::AUTO_WRITE
     ),
     mesh
);
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Old   November 25, 2010, 10:04
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Yes I just do it.
Then I would join electrostaticFoam with my_simpleFoam, so I'll modify createFieds.h and my_simpleFoam.c adding electrostaticFoam. It's correct?
But can I impose different boundary condition on the same patch? Example:
symmetryPlane for potential (for electric fields) and
zeroGradient for U (Velocity fields)

Thanks
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Old   November 26, 2010, 06:21
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Yes, of course boundary conditions are separate for every field. Otherwise you'd have a tough time even simulating a lid driven cavity
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