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Numerical schemes: under the hood

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Old   March 9, 2012, 04:54
Default Numerical schemes: under the hood
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Samuele Z
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Dear foamers,

I am interested in finding out how the different numerical schemes available in OpenFOAM work.

I would like to understand some details. Is there any documentation available and/or which are the files in the src where they are expliceted?

Thanks a lot,
Samuele
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Old   March 9, 2012, 05:29
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Hi,

you can browse the doxygen http://www.openfoam.org/docs/cpp/
http://foam.sourceforge.net/docs/cpp...c3619d681.html might be what you looking for
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Old   March 9, 2012, 05:31
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Samuele Z
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Thanks Elvis,

that's could be a good starting point. Also, do you know if a more `theoretical' documentation exists?

Thanks,

Samuele
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Old   March 9, 2012, 06:59
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And how can I understand which is the best numerical scheme for each solver?

Thanks again,
Samuele
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Old   March 9, 2012, 08:00
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Any textbook on CFD will give information on numerical scheme and how they are defined and can be related to stability and stuff like that.

Which schemes you should use depends on the case more than the solver.
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Old   March 9, 2012, 09:50
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Samuele Z
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Dear Bernhard,

thanks for answering.

Actually, I agree when you say that I should read a book about Fluiddynamycs.

The point is that I would like to find a book which uses the names used by OF. For example, reading here, if I have to solve a laplacian I can write:

laplacian(nu,U) Gauss <interpolationScheme> <snGradScheme>

What I would like to und is what is it meant by <interpolationScheme> and by <snGradScheme>.

Could you give me a brief explanation? Or a link?

Thanks a lot.

Samuele
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Old   March 9, 2012, 11:22
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Hi,

if you take a look at the PHD thesis collection from Dr. Jasak http://powerlab.fsb.hr/ped/kturbo/OpenFOAM/docs/ you find OF based/releated CFD-reseach, but the syntax is not source code like you could find s.th. like that in the OF wiki but those Documentations are hiden somewhere in the wiki. Holger Marschall had a docu project in mind, but he was stopped by somebody´s lawyers (who owns a copyright.)

you know Hakan´s Stuff allready?
http://www.tfd.chalmers.se/~hani/kurser/OS_CFD_2011/
..2007

or the Gothenburg OpenFOAM workshop Penn State OF Workshop training Summerschool stuff etc.
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Old   March 12, 2012, 04:22
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Samuele Z
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Hi Elvis,

thanks for help.

Actually, I am finding out something very interesting.

I have a questio: do you know why the `linear' interpolation scheme is a second order scheme?

Being linear, shouldn't it be first order?
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Old   August 25, 2014, 09:57
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Pratik Nanavati
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Quote:
Originally Posted by samiam1000 View Post
Hi Elvis,

thanks for help.

Actually, I am finding out something very interesting.

I have a questio: do you know why the `linear' interpolation scheme is a second order scheme?

Being linear, shouldn't it be first order?
Hello Samuele,

this post is almost 5 years old. but i am new to openfoam. i also have the same question.
i.e. complete description of fvSchemes in OpenFoam terms (well documented).

(I read the Elvis's suggestions as well in the thread)

have u found any ? if yes, can you please paste the link or share any material over the email ?
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Old   August 26, 2014, 05:06
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Hi,
there is a very slooowly improving initiative
http://www.cocoons-project.org/ The goal of the CoCoons Project is to provide peer and technical reviewed, high-quality documentation of C++ libraries for Computational Continuum Numerics on Arbitrary Unstructured Meshes in the Open Source Spirit (OSS).

Asking your Question at the http://www.extend-project.de/ =>OpenFOAM Community (OF-extend people) might lead to some information.

http://www.sourceflux.de/book/
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Old   August 26, 2014, 06:56
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Pratik Nanavati
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thanks for the suggestion elvis
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Old   December 9, 2014, 06:51
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Tobias Adam
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Hey everyone

I try to find an explantation to the fv-schemes.
I shortly searched on the pages elvis suggested, but there is so much information on that many pages that I just don´t know where to start to find the information about the schemes.

I know how to use the main schemes. But I like to understand all schemes from this list.

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


Best regards Tobi
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Old   December 9, 2014, 07:00
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Tobias Adam
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Hmm,
I cannot edit the post!?
Maybe cfd-online does not work very well with google chrome?
EDIT:
Right link to the list of schemes I´m interested in:

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

best regards Tobi
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