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mastering fvSchemes in OpenFOAM

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Old   July 20, 2013, 08:12
Default mastering fvSchemes in OpenFOAM
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Zifei Yin
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Its easy to use Gauss upwind and Gauss linear in OpenFOAM with good robutness. However, when I used other fvSchemes like MUSCL, Fourth etc. It often turns out to be EOF error.

I'd like to know the reason behind it and the way to master using fvSchemes in OpenFOAM.

Many thanks!
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Old   July 20, 2013, 09:48
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Hi yzf1215,

Several of the schemes you can select in the fvSchemes-file require a number of arguments (either floats or words). When you get an EOF error it could indicate that you didn't provide them.

Cheers,

Lieven
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Old   August 9, 2013, 15:06
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Quote:
Originally Posted by Lieven View Post
Hi yzf1215,

Several of the schemes you can select in the fvSchemes-file require a number of arguments (either floats or words). When you get an EOF error it could indicate that you didn't provide them.

Cheers,

Lieven
Hi lieven
how should we provide them for removing this error,
when i change the Guass Upwind for "di(phi ,omega)" to Guass linearupwind i also get this error,
i thank you if you explain it more
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Old   August 9, 2013, 15:40
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Hi
set it to Gauss linearUpwind phi; for example.or Gauss linearUpwind grad(omega);
and then define grad(Omega) in grad dictionary.both of these terms indicate the direction of flow(that divergence should act at that direction) for solver.hope be solved by this.
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Old   August 9, 2013, 15:40
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Have a look at http://www.openfoam.org/docs/user/fvSchemes.php
there you have a few examples given...

Cheers,

L
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Old   August 9, 2013, 16:10
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i get it dear lieven & dera ehsan
thank you
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Old   August 11, 2013, 04:29
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Originally Posted by immortality View Post
Hi
set it to Gauss linearUpwind phi; for example.or Gauss linearUpwind grad(omega);
and then define grad(Omega) in grad dictionary.both of these terms indicate the direction of flow(that divergence should act at that direction) for solver.hope be solved by this.
Dear Ehsan,
are thease two divergence schems the same? "Gauss linearUpwind phi" & "Gauss linearUpwind grad(omega)"
if yes, phi means grad(omega)?

is it true to write Gauss linearUpwind grad(U) instead of Gauss linearUpwind grad(omega)?
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Old   August 11, 2013, 04:38
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no they are different by themselves but "here" they have the same role of showing direction to the solver.
for Omega you better use grad(Omega) and for U,grad(U) for more clarification.but both show direction of flow for calculation of terms.
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Old   August 11, 2013, 04:47
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no they are different by themselves but "here" they have the same role of showing direction to the solver.
for Omega you better use grad(Omega) and for U,grad(U) for more clarification.but both show direction of flow for calculation of terms.
i can understand that what is the grad(omega) is, but i can understand what is the phi?
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Old   August 11, 2013, 04:51
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Since linear upwind has the additional term r.grad(omega) in the case of div(omega), I would prefer grad(omega).
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Old   December 4, 2014, 10:34
Default fv-schemes
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Tobias Adam
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Hey everyone

I try to find an explantation to the fv-schemes.
I know how to use the main schemes. But I like to understand all schemes from this list.
Does anyone know where to find information about these.
Information could be anything like, the mathematical explanation the fv-schemes ( still I donīt understand c++) or descriptions about when to use which scheme.

The schemes I want to know about are listed in this document:

https://docs.google.com/document/d/1...it?usp=sharing

Tomorrow Iīm going to ask someone to help me with C++, but I would be happy for each kind of information :-)

Best regards Tobi
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Old   December 5, 2014, 04:23
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Tushar Chourushi
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Hello Tobi Adam,

I guess there was discussion on the forum sometime back. I think you should have a look to the post referred below.

Numerical schemes: under the hood


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Best Luck!
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