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Old   July 8, 2010, 18:34
Default Understanding icoFoam.C
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Pascal
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Hi all,

After looking at this web page : http://openfoamwiki.net/index.php/IcoFoam
I still had one question :

I assume that:
Code:
        fvVectorMatrix UEqn
        (
            fvm::ddt(U)
          + fvm::div(phi, U)
          - fvm::laplacian(nu, U)
        );
is equivalent to :

Code:
         fvVectorMatrix UEqn = fvm::ddt(U) + fvm::div(phi, U) - fvm::laplacian(nu, U)
Am I right ?

If yes, what does the following code mean? :
Code:
fvScalarMatrix pEqn
                (
                    fvm::laplacian(rUA, p) == fvc::div(phi)
                );
I know it define the pressure equation 'pEqn'. How Is pEqn obtained? Is it possible to write a similar equation as the one obtained for UEqn (UEqn = ...)?

Thank you,

Pascal
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Old   July 9, 2010, 03:05
Default how derive the pressure equation
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Jianye Xia
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i have also the same question about the pressure equation.
Can anybody explain how this equation is derived?
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Old   July 9, 2010, 11:24
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David Gaden
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Look at Hrvoje Jasak's PhD thesis. The link is at the top of the wiki page you posted:

http://openfoamwiki.net/index.php/IcoFoam

He uses the same annotation there as OpenFOAM. The pressure equation is derived in section 3.8.1 starting on page 145.
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Old   July 9, 2010, 11:47
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Pascal
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Thank you!

So it iterate over 'p' and when the equality is reached p become pEqn as describe in equation 3.141 in Jasak's thesis.

Am I right?

Pascal
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