How to add transport equations

alimansouri · January 8, 2009, 17:16

Hi guys

I am trying to simulate a simple mixing problem,
2D, single phase, turbulent and mixing in cross flow jets...

how can I add two species equations? should I use turboFoam ?

is there any tutorial etc ?

thank you!
Ali.

villet · January 9, 2009, 05:37

Hi Ali,

here's a simple example how to add a (passive) scalar to an existing solver:

http://openfoamwiki.net/index.php/Ho...ure_to_icoFoam

The example is for laminar solver, but in the similar way you can start from turbulent flow solver. "simpleFoam" is for steady-state problems and "turbFoam" for transient problems.

Hope this helps!

Ville

alimansouri · January 9, 2009, 17:05

thanks Ville!

have you seen any tutorial in this area ?

Ali.

villet · January 11, 2009, 07:33

At the end of the wiki webpage there is a case file for the cavity flow case. But once you have created the solver, most of the work is done. Then you can just apply it to your case.

Or if you insist to have a simpler case, you can first modify icoFoam elbow mixing tutorial for one passive scalar.

alimansouri · January 12, 2009, 15:00

Hi Ville

If I would like to have two passive scalars, then should I add two equations ?

since in Fluent you add only one and the second one its just decuction from the whole field (e.g. concentration).

do you also have any idea about this error

Foam Fatal error" attempt to read beyond EOF"

thanks alot!

villet · January 12, 2009, 15:46

Yes, that's correct. Two equations for two passive scalars. Twice as much to write

I'm not sure what you mean about Fluent? Practically you can do the same thing with Fluent and OpenFOAM.

The last error... check your code if you're missing any closing parenthesis or ";".

Good luck with foaming!

gschaider · January 12, 2009, 16:20

Hi Ali!

What you're talking about ("in Fluent") is the case that for the two scalars the relation s1+s2==1 is always true (because there are no other species)?

In that case you can always solve for s1 and then calculate s2=1-s1

Bernhard

January 8, 2009, 17:16	Hi guys I am trying to simu	#1
alimansouri New Member Ali Mansouri Join Date: Mar 2009 Posts: 15 Rep Power: 17	Hi guys I am trying to simulate a simple mixing problem, 2D, single phase, turbulent and mixing in cross flow jets... how can I add two species equations? should I use turboFoam ? is there any tutorial etc ? thank you! Ali.

January 9, 2009, 05:37	Hi Ali, here's a simple exa	#2
villet Member Ville Tossavainen Join Date: Mar 2009 Posts: 60 Rep Power: 17	Hi Ali, here's a simple example how to add a (passive) scalar to an existing solver: http://openfoamwiki.net/index.php/Ho...ure_to_icoFoam The example is for laminar solver, but in the similar way you can start from turbulent flow solver. "simpleFoam" is for steady-state problems and "turbFoam" for transient problems. Hope this helps! Ville

January 9, 2009, 17:05	thanks Ville! have you see	#3
alimansouri New Member Ali Mansouri Join Date: Mar 2009 Posts: 15 Rep Power: 17	thanks Ville! have you seen any tutorial in this area ? Ali.

January 11, 2009, 07:33	At the end of the wiki webpage	#4
villet Member Ville Tossavainen Join Date: Mar 2009 Posts: 60 Rep Power: 17	At the end of the wiki webpage there is a case file for the cavity flow case. But once you have created the solver, most of the work is done. Then you can just apply it to your case. Or if you insist to have a simpler case, you can first modify icoFoam elbow mixing tutorial for one passive scalar.

January 12, 2009, 15:00	Hi Ville If I would like to	#5
alimansouri New Member Ali Mansouri Join Date: Mar 2009 Posts: 15 Rep Power: 17	Hi Ville If I would like to have two passive scalars, then should I add two equations ? since in Fluent you add only one and the second one its just decuction from the whole field (e.g. concentration). do you also have any idea about this error Foam Fatal error" attempt to read beyond EOF" thanks alot!

January 12, 2009, 15:46	Yes, that's correct. Two equat	#6
villet Member Ville Tossavainen Join Date: Mar 2009 Posts: 60 Rep Power: 17	Yes, that's correct. Two equations for two passive scalars. Twice as much to write I'm not sure what you mean about Fluent? Practically you can do the same thing with Fluent and OpenFOAM. The last error... check your code if you're missing any closing parenthesis or ";". Good luck with foaming!

January 12, 2009, 16:20	Hi Ali! What you're talking	#7
gschaider Assistant Moderator Bernhard Gschaider Join Date: Mar 2009 Posts: 4,225 Rep Power: 51	Hi Ali! What you're talking about ("in Fluent") is the case that for the two scalars the relation s1+s2==1 is always true (because there are no other species)? In that case you can always solve for s1 and then calculate s2=1-s1 Bernhard __________________ Note: I don't use "Friend"-feature on this forum out of principle. Ah. And by the way: I'm not on Facebook either. So don't be offended if I don't accept your invitation/friend request

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