CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   Phoenics (http://www.cfd-online.com/Forums/phoenics/)
-   -   some questions on BFC (http://www.cfd-online.com/Forums/phoenics/51681-some-questions-bfc.html)

wyh October 28, 2003 06:51

some questions on BFC
 
Anyone has any experience on using Body-Fitted Coordinate system? I have run some cases created by myself, but no one can run normally, when I run earth, it will stop, I have changed the initial conditions, relaxation factors, variable ranges, nothing can help me? anyone here can give some suggestions?

Thanks

Rami October 29, 2003 02:22

Re: some questions on BFC
 
wyh,

What exactly is the problem?

If you wish to see whether it is caused by the BFC, maybe you can set up a simple case. I would suggest a heat conduction problem (i.e., no velocity, a single scalar) with constant conductivity over a simple doamain (e.g., a square), BUT DEFINED AS BFC with the simplest BC possible (e.g., insulation on two opposite faces, prescribed temperatures on the others). Probably you can even find an analytic soluton for such a case.

In this way you would be able to solve the case with non-BFC grid and see you get a reasonable agreement with the exact solution. Then switch to a BFC grid and see if you get similar solution or have problems. Then you will be able to better identify the difficulty. Having it removed, you may then gradually complicate the problem until you return to your original case (what is it, actually?).

I hope it helps,

Rami

wyh November 3, 2003 09:33

Re: some questions on BFC
 
Dear Rami, Thanks for your kind help. What I want to do is to simulate the smoke flow in a building due to a fire. I have tried a lot of simple cases e.g. fire occures in a room with regular shape, but when running the earth, it cannot go on. since I have no experience on BFC before, I do not know what to do about this. can you give me some simple example of yours? Thanks in advance.

Rami November 3, 2003 10:12

Re: some questions on BFC
 
I am afraid I don't have a simple case at hand, and I am quite busy right now. You can find simple cases in the standard library cases and probably also in the tutorials. There should be also lectures and encyclopaedia entries on BFC.

wyh November 11, 2003 04:19

Re: some questions on BFC
 
Dear Rami, Thanks


All times are GMT -4. The time now is 03:22.