implementation of schemes in openfoam
 

dear all,
i have one question, what is the procedure to make customised schemes in openFoam i mean other than existing schemes in openfoam. i need to implement the schemes like upwind.

thanks in advance

with regards
venkataramana

Upwind schemes are implemented a long, long time ago, see here how to use them: http://www.openfoam.com/docs/user/fvSchemes.php

what i mean to say the schemes other than upwind, linear which are available in openFoam, How to develop a new scheme and how to run it.

thanks for your reply,

I would it something like this: Start from an existing scheme that looks like the one you are looking for, copy them in your own folder, adjust to your wishes, compile into a library, and call that using controlDict from your simulation.

thank u very much, i will try it

Hi Bernard,
I have a doubt similar to Venkataramana's. Which file I have to edit to modify the van Leer scheme?
Thanks,
Paulo Vatavuk

See vanLeer.H

Hi Anton,
Thanks for the hint. I’ve been navigating the code documentation for almost one hour, but I can’t find the point were the vanLeerLimiter class is instantiated. I want to understand were the LimitedScheme parameter is defined. I’ve been studying C++ for some time but I’m still thinking in the FORTRAN way. Can you help me?
Thanks,
Paulo

It's a bit tough to find where it is instantiated because the trail breaks due to the use of macros. If you just want to implement a different limiter, just stick to vanLeer.H (updated link) and edit the limiter function there.

hi,
 

where should i call in controlDict file..

Hi Anton,
Thanks for the help.
Paulo

hi vatavuk,
 

can u write a procedure, to edit any scheme with steps in openFoam. i need to edit Gauss linear scheme.

thank u,

Hi Venkataramana,
I'm still trying to figure out how to do it. I suspect that creating a new scheme is more or less like creating a new boundary condition or a new turbulence model, because they all are runtime selectable. I found a programming tutorial that may help:
http://cfd.iut.ac.ir/files/Tutorial,...20Diego%20.pdf
Best wishes,
Paulo

Sorry I dupplicated the above post and I don't know how to remove it.

schemes
 

Dear all openfoam users,

where exactly the code for the following upwind scheme is available in openfoam,

http://s0.wp.com/latex.php?latex=%5C...&fg=333333&s=0.
if i want to edit the linear upwind scheme in to 2 nd order and 3rd order and how to implement it ( I mean procedure)
anybody implemented any schemes in open Foam.
Thanks in advance.

Dear foamers,

it has been a while since this post has been made. But I am still facing the same question. Where exactly can be found the implementation of the upwind scheme, or higher order convection schemes (deferred correction, k-scheme) in OpenFOAM?

See also this thread that I opened.

http://www.cfd-online.com/Forums/ope...on-scheme.html

Thank you very much for your answers!
Anne

Hi Anne,

I am facing the same problem. Basically I would like to modify an existing scheme but I could not find where the scheme is defined. By following this path:

src/finiteVolume/interpolation/surfaceInterpolation/limitedSchemes

I found the "interpolation_scheme".H files, but I am afraid that they are related to the limiter of that "interpolation_scheme".

Did you sort out the problem, by any chance?

Cheers!
Paolo

Dear Paolo,

I don't know it will be of any use to you but I think you should refer the following cfd-online post:

http://www.cfd-online.com/Forums/ope...tml#post348575

-
Best Luck!

Greetings to all!

@Tushar & Paolo
It is because of NDA (https://en.wikipedia.org/wiki/Non-disclosure_agreement). Detailed information of OpenFOAM comes under NDA

Check this out
http://www.cfd-online.com/Forums/ope...tml#post531559

:)

@Tushar
Thank you very much for your reply. I have already had a look on th e post you suggested me but I couldn't find a solution to my problem.

@Andrew
Thanks to you too. I have also seen the post you suggested about the NDA and I think I am in a different situation. In that post they were talking about a particular case posted by the thread starter. If the case is under NDA, you cannot share information about your results whit other people. In my case I have just asked Anne if she had sorted out her problem and asked where I could find the OpenFOAM file I would like to modify.


Cheers to you All!
Paolo

@Paolo
Its up to you to accept the facts or ignore

All I can say..
Good Luck

Hi Andrew,

I just thought that in principle it is possible to modify everything in OpenFOAM. I do not know, maybe I am wrong.
Anyway, many thanks for the advice!

Cheers,
Paolo

Dear Paolo,

it has been a while since I dealt with this problem. Here, what I found out a while ago for the LUDS scheme

The weights for the surface interpolation are computed in the method linearUpwind.C
and used in the method surfaceInterpolationSchemes.C in
src/finiteVolume/interpolation/surfaceInterpolation/surfaceInterpolationScheme

In linearUpwind.C the method upwind.H is called from
src/finiteVolume/interpolation/surfaceInterpolation/limitedSchemes/upwind In upwind.H the weights are computed according to the UDS scheme, setting  = 1 if the flux is greater
than zero and  = 0 else.

The explicit correction via the gradient
is added in the method linearUpwind.C in
src/finiteVolume/interpolation/surfaceInterpolation/schemes/linearUpwind

I hope this helps?

Kind Regards
Anne

Hi Anne,

Thank you very much for your answer, for your time, and sorry for the belated reply.

Your reply helped me a lot. However, I am still trying to understand how to get the scheme I want, but seems that it will be as much harder as expected. At least, by considering what you said, now it seems that it would be possible... I just need time to understand the structure of the software.

Thanks once again!

Kind Regards,
Paolo

laplacian scheme
 

can anyone suggest which one scheme is to be choosed in case of enthalpy updating method for phase change material.