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-   -   How to relate what I learned about CFD with OpenFOAM's implementation of CFD? (https://www.cfd-online.com/Forums/openfoam/169290-how-relate-what-i-learned-about-cfd-openfoams-implementation-cfd.html)

sversutc April 7, 2016 02:22

How to relate what I learned about CFD with OpenFOAM's implementation of CFD?
 
I'm a beginner on CFD and OpenFOAM and I have studied the Finite Volume Method (some part) with books like Versteeg, Maliska, etc. I begun to understand some things about this issue, but when I started to do some tutorials of OpenFOAM, I couldn't align the theory to the practice, because the tutorials I use seems to focus on the technical part.

I don't know how to apply the knowledge I'm acquiring on CFD on the software. I never saw a tutorial of the software explaining and showing how the software deals with things like implicit and explicit discretization, upwind, central difference, multigrid, coupled and separated systems, etc and how can I manipulate this in the codes.

Am I learning it wrong? How can I proceed to learn this 2 subjects together? Or the better way is to learn them separated and with the experience begin to understand this thing?

Thanks!

chriss85 April 7, 2016 04:44

You can change the used schemes in the fvSolution file. I suggest trying some example case and playing with the schemes. You can find some good stuff about the convective term here: http://www.holzmann-cfd.de/index.php...erical-schemes

Bazinga April 7, 2016 10:35

Quote:

Originally Posted by sversutc (Post 593797)
I'm a beginner on CFD and OpenFOAM and I have studied the Finite Volume Method (some part) with books like Versteeg, Maliska, etc. I begun to understand some things about this issue, but when I started to do some tutorials of OpenFOAM, I couldn't align the theory to the practice, because the tutorials I use seems to focus on the technical part.

I don't know how to apply the knowledge I'm acquiring on CFD on the software. I never saw a tutorial of the software explaining and showing how the software deals with things like implicit and explicit discretization, upwind, central difference, multigrid, coupled and separated systems, etc and how can I manipulate this in the codes.

Am I learning it wrong? How can I proceed to learn this 2 subjects together? Or the better way is to learn them separated and with the experience begin to understand this thing?

Thanks!


Dear sversutc,

to define the things you mentioned you should check the fvSolution and fvSchemes files in the system dir. In the fvSolution file you will find (and should define) information about solving the algebraic systems of equations for example multigrid techniques, pressure velocity coupling, residuals etc.
In the fvSchemes files you will define information regarding the FVM: discretization in time and space (Some keywords you mentionend: implicit methods, explicit methods, CFD, upwind, etc...).

I would propose to check the OpenFOAM Userguide for the various options that you have in the fVSchemes and fVSolution files. Then use the keywords that you find there (For example GAMG for multigrid techniques) and search the web and especially this forum for more information.


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