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-   -   How can we use simpleFoam for laminar flow (https://www.cfd-online.com/Forums/openfoam-solving/82242-how-can-we-use-simplefoam-laminar-flow.html)

anijdon November 21, 2010 02:24

How can we use simpleFoam for laminar flow
 
Hi,
I want to simulate an incompressible laminar flow in steady state.
I know, I should use simpleFoam but I don't know how:o
please tell me How can I do it.
thank you

tcarrigan November 21, 2010 13:57

Just set the turbulence model to laminar in RASProperties dictionary.

anijdon November 22, 2010 02:50

hi;
thanks for your help.but I couldn't change any word or number in RASProperties because it's zipped in utilities simpleFoam examples.How can I do it?
and my other problem is that I didn't detetrmine any parameter like epsilon, k, nuTilda, and R in my own case because I didn't need them in laminar flow. is it a mater? if no should I omit these terms in transportProperties or in fvSchems and fvSolution or in simpleFoam's main code?
thanks.

tcarrigan November 22, 2010 11:43

I think it would be best for you to look through the pitzDaily simpleFoam tutorial. The idea when setting up an OF case is to copy an existing tutorial to your run directory and edit the existing files. In the pitzDaily tutorial you will find RASProperties dictionary and all the other files you need. Simply change the turbulence model to laminar, and that's it.

You will not need k, epsilon, etc.. in you 0/ directory because you will be doing a laminar simulation. Therefore, you can also remove references to these terms in the fvSchemes and fvSolution dictionaries. However, there shouldn't be any reference to these terms in the transportProperties dictionary.

And unless you are going to write your own solver and compile it, try not to edit any of the solvers source code, there's no need to do that when setting up a case.

Hope this helps.

anijdon November 22, 2010 15:18

thanks for your guide. I looked to that case of tutorial and copied it in run directory bat as I said before I can't change the RASProperties code because it's zipped in kuunto version of linux and OpenFOAM-1.5-dev that I'm using. It's my problem. also I tried to make another RASProperties code but I didn't know how could I put it into a zipped file. to run the case correctly.
again I thank you for your helping.

tcarrigan November 22, 2010 15:47

I'm not quite sure why RASProperties is zipped, unless you haven't unpackaged and built OpenFOAM.

anijdon November 23, 2010 07:39

my problem was resolved and I want to thank you for your kindness.
I wish I would have your guides in future.
thanks a lot ,
Good luck:)

anijdon November 30, 2010 05:55

Hi,
excuse me, I came across another problem.
When I had deleted the wallFunctionCoeffs from RASProperties as turbulance parameters, I abserved this error:
keyword wallFunctionCoeffs is undefined directory "/home/.../constant/ RASProperties"
However the wallFunctionCoeffs are determined for turbulence flow.
I think, these properties effect in the results, and I don't know what should I do?
thanks

T.D. November 30, 2010 07:30

Hi, you can simply re copy it from an existing example.
Good Luck

anijdon November 30, 2010 08:49

I know, but it reply me to enter wallFunctionCoeffs however I don't need them for my own case (laminar flow).
You think entering these prperties dosn't effect in the result of laminar flow?

T.D. November 30, 2010 11:02

Quote:

Originally Posted by anijdon (Post 285397)
I know, but it reply me to enter wallFunctionCoeffs however I don't need them for my own case (laminar flow).
You think entering these prperties dosn't effect in the result of laminar flow?

did you put in transportproperties file:

RASModel laminar;

turbulence off;

printCoeffs off;

anijdon November 30, 2010 14:46

Yes,I did. But I don't know what's the problem:confused:.
why does it ask me these coefficients and not other coefficients?
thank you.

anijdon December 1, 2010 02:26

Quote:

Originally Posted by T.D. (Post 285430)
did you put in transportproperties file:

RASModel laminar;

turbulence off;

printCoeffs off;



excuse me, can we use icoFoam in steady state if my problem has not be resolv?how?

T.D. December 1, 2010 03:52

Quote:

Originally Posted by anijdon (Post 285523)
excuse me, can we use icoFoam in steady state if my problem has not be resolv?how?

yes , but you must change the ddtSchemes in the system/fvSchemes to "steadyState".
Good Luck


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