CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   FLUENT (http://www.cfd-online.com/Forums/fluent/)
-   -   temperature limited to 1 in only one cell ??!!! (http://www.cfd-online.com/Forums/fluent/65981-temperature-limited-1-only-one-cell.html)

pipin July 2, 2009 09:47

temperature limited to 1 in only one cell ??!!!
 
Hi,

I've an unsteady problem, coupling fluid and solid domain.
After 5s calculation, i've a message ' temperature limited to 1.000 in 1 cell'
this cell is between a solid and gaseous zone, but doesn't stop the convergence...

In the gaseous zone, i use the DTRM model and k-epsilon with Non equilibrium model. The mesh has a correct skewness (<0.9).

Thanks for reply

pipin July 20, 2009 07:56

Hi,
I have not managed to solve the problem if someone have solution, I shall be very grateful

Piotrek July 20, 2009 08:32

Quote:

Originally Posted by pipin (Post 223295)
Hi,
I have not managed to solve the problem if someone have solution, I shall be very grateful

Hi what you can try to do is try to find this bad cell, for example by Display->Iso-surface and than adjust mesh in that place.

You can also go to solve/monitors/limits and change temperature limit.
You can also let it be for a couple of iterations and temperature in that cell might stabilize.

Good luck

pipin July 21, 2009 09:48

thanks,
But after many iterations, this problem spreading to other cells whereas it is in a solid that heats slowly and that the mesh quality is good (skewness < 0.9), these cells are adjacent to one side adiabatic.
I want to reduce the UDR of energy?
What do you think? do you have other ideas?

Piotrek July 21, 2009 10:53

Hi,
you can lower the URF, although if the number of cells is going up it will eventually go down and lower URF will only postpone this. If it doesn't start stabilizing and going down than you will have a divergent case.

Question is than, what sort of temperature are you suppose to get in this cell and why the limit is so low (1000K)?

pipin July 21, 2009 10:58

The temperture is lower than 1 and not 1000 K...it's in a zone where the temperature is equal to 293K and heat slowly...
I think i will make again the mesh...


All times are GMT -4. The time now is 17:47.