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Can laplacianFoam solve transient heat conduction equation?

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Old   January 30, 2020, 13:52
Default Can laplacianFoam solve transient heat conduction equation?
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Mandeep Shetty
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It is my understanding that the laplacianFoam solver is used to solve the Laplace equation that arises during some modeling. But Laplace equation doesn't have a transient term or source term. So how can the laplacianFoam solve the transinet heat conduction equation? Shouldn't it be named 'diffusionFoam'?
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Old   February 13, 2020, 17:33
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I would create a feature request issue in GitLab.

Having said that, usually, once a name for a functionality is released, it stucks even though more suitable alternatives emerge in the course of time, because of a virtual must to ensure the backward compatibility. Workflows of users should not be broken unless becomes a must.

If there would be very few users for OF, it would be very easy to make such changes. OF has a large habitat nevertheless, so any change will disturb the users and developers.

So why bother? Living with it is wise for such matters.
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Old   February 18, 2020, 04:51
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Dear all,

I cannot agree about the statement that the laplacianFoam does not include the time derivative. So if you check the code we certainly see:

Code:
fvScalarMatrix TEqn
(
    fvm::ddt(T) - fvm::laplacian(DT, T)
    ==
    fvOptions(T)
);
I clearly can see the time derivative. Nevertheless, I have to say that for temperature depended on properties, the solver is not suited. So summing up:
  • Time derivative available
  • Laplacian term available
  • fvOptions for source / sink modeling available
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Old   February 18, 2020, 07:24
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Quote:
Originally Posted by Tobi View Post
Dear all,

I cannot agree about the statement that the laplacianFoam does not include the time derivative. So if you check the code we certainly see:

Code:
fvScalarMatrix TEqn
(
    fvm::ddt(T) - fvm::laplacian(DT, T)
    ==
    fvOptions(T)
);
I clearly can see the time derivative. Nevertheless, I have to say that for temperature depended on properties, the solver is not suited. So summing up:
  • Time derivative available
  • Laplacian term available
  • fvOptions for source / sink modeling available
Laplacianfoam solver does include the time derivative, but my question was regarding the Laplace equation which doesn't include a time derivative. Renaming the solver may be difficult, but it should be mentioned somewhere that it's not the Laplace equation but the diffusion equation which is being solved in the Laplaicanfloam solver.
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Old   February 18, 2020, 13:19
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Would you please make a feature/documentation request in GitLab, if possible, then by referring this CFD-Online thread: GitLab-Issuer.

Last edited by HPE; February 18, 2020 at 16:52.
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Old   February 18, 2020, 16:45
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Ah got it. Sorry.

So actually the laplacianFoam should not include the time derivative. I am not sure but I had the feeling that it was once without the time derivative. Nevertheless... I got your point

If I am still not on the right way, please just write down the equation
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