CFD Online Discussion Forums

CFD Online Discussion Forums (
-   OpenFOAM Running, Solving & CFD (
-   -   BouyantFoam (

antopnieta January 30, 2008 08:23

I'm new with OpenFoam and I ha
I'm new with OpenFoam and I have a question about BouyantFoam:

If fvSolution of BouyantFoam works with PISO, also i have to write rho, h, k, etc in SOLVERS?? If this not the case, where put this constants?


evan January 30, 2008 13:22

Hi Antonieta, You mis-spell
Hi Antonieta,

You mis-spelled Buoyant in your title. You might try here for some answers, as this title (correctly spelled) is already on the lists.

Briefly, you need to look at the solver. buoyantFoam uses the heatTransfer solver located here:


So, even though I haven't used this solver before, I just look at buoyantFoam.C and createfields.H, and immediately see that rho and h are being declared through the thermophysicalmodels directory in the src directory; in particular, they are unknowns here that are beings solved, and not constants. If you want to see this in paraview, then I think you need to create an IOobject for, say, the enthalpy; which is not currently listed in createFields.H.

Anyway, I would recommend reading through a bunch of the discussion here, the user and programmers manual, and then take a look at the code for the solver. Things should start to become clearer at that point.

Hope this helps some.

antopnieta January 30, 2008 15:25

Dear Evan: Thank for your a
Dear Evan:

Thank for your answer!

First at all, yes, it's BuoyantFoam and not Bouyant.

Second... how I create an IOobject?? or where I find how create...

I read a lot about this, but there a lot of things that I don't understand yet, and this is one of them... for this reason I asked...

Thank again..


evan January 30, 2008 15:58

Maybe try to add in createfiel
Maybe try to add in createfield.H, for the h field for example, the following:

volScalarField h

remove the volScalarField& h assignment, recompile. and try the case again.


antopnieta January 30, 2008 16:32

Dear Evan: When I do that,
Dear Evan:

When I do that, I should see a new field h?? something happen when I do that?? Because all is the same...

Sorry for the basic questions but I never do this before...


evan January 31, 2008 15:42

Hi Antonieta, Not sure what
Hi Antonieta,

Not sure what to tell you right now. I think that should have worked. Are you sure the field isn't being written in your case file? I will try it here in the next couple days on the buoyantFoam tutorial to see if it works for me (sorry, I am a bit busy at the moment), but I have done this for other solvers without trouble.

You could also change the IOobject to mesh and MUST_READ, like explained here:

But then you might need to write a boundary condition for the field in the tutorial 0 time directory.

Good luck.

evan February 1, 2008 20:08

Antonieta, Yeah, sorry, so

Yeah, sorry, so my suggestion didn't work; I just tried it myself. Tried a couple of other things, but to no avail. I'll keep at it, and let you know if I figure it out.


stefan February 4, 2008 08:20

Hi, I'm a new user of OpenFOAM
Hi, I'm a new user of OpenFOAM and I have a little problem.

I want create a room with a radiator. At first I use buoyantSimpleFoam ... but I think thats not the best Solver, because it is for steadystate. Therefore a try it with buoyantFoam. My problem is deltaT, because U should be 0. (deltaT=Co*dx/U) How I define deltaT?

thanks for your help!

antopnieta February 4, 2008 08:22

Evan: Thank... i tried othe

Thank... i tried other things too, but i I haven't had success.

I hope you have luck..


All times are GMT -4. The time now is 01:37.