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October 4, 2013, 08:00 |
Diffusion term in OpenFOAM
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#1 |
New Member
Matthias Stammen
Join Date: Oct 2010
Posts: 8
Rep Power: 15 |
Hello,
checking the term turbulence->divDevReff(U) I came up with the following question: The diffusion term for incompressible flows should look somehow like this (here, I ignored the viscosity): fvc::div(fvc::grad(U)+fvc::grad(U)().T())And this can be transformed to this: fvc::laplacian(U)But when I implement that into OpenFOAM, those terms give different results. I assume it is connected to the discretization schemes, but even when I use linear for all schemes, it gives me different results. So, what do I do wrong? What do I miss? Is it because of wall-functions or boundary conditions? Any comment is appreciated... Regards, Matze |
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February 12, 2014, 09:23 |
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#2 |
Senior Member
Joachim Herb
Join Date: Sep 2010
Posts: 650
Rep Power: 21 |
I think this wiki page might explain what is going on here:
http://openfoamwiki.net/index.php/Bu...DevReff.28U.29 Also have a look at this thread (the difference between compressible and incompressible models goes away if the continuity equation is fulfilled after convergence of the solution): http://www.cfd-online.com/Forums/ope...ivdevreff.html |
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February 12, 2014, 09:43 |
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#3 | |
Senior Member
Bernhard
Join Date: Sep 2009
Location: Delft
Posts: 790
Rep Power: 21 |
Quote:
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February 12, 2014, 09:55 |
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#4 |
New Member
Matthias Stammen
Join Date: Oct 2010
Posts: 8
Rep Power: 15 |
Hello,
thank you for your reply, it was very helpful! Regards, Matze |
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