CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   FLUENT (http://www.cfd-online.com/Forums/fluent/)
-   -   fluent define limiting time (http://www.cfd-online.com/Forums/fluent/83534-fluent-define-limiting-time.html)

nuengao January 3, 2011 02:13

fluent define limiting time
 
Dear all
please give me your suggestion about how to set fluent simulation for limiting time. for example

http://img9.imageshack.us/img9/6762/conjugate.jpg

I have model as shown upper figure.

fluid inlet: 1.8 m/s, 588 k
fin that is surrounded by fluid: 273 k teperature
outlet: outflow

the fluid will transfer the heat to the fin.

I'd like to use CFD postprocessing(temperature contour) after 20 second.
please help me

nuengao January 3, 2011 03:10

Can I set time to Transient on General settings and set the Run calculation as following:

Time step size(s)=1
number of time steps= 20
max Iterations/TIme step= 10

Could anyone give me your suggestion that it is correct or not? please

ComputerGuy January 3, 2011 22:07

Nuengao,

Your approach is correct. The final time of the simulation will be:

N*\Delta t

Where N is the number of time steps and \Delta t is the time step size.

Typically, having a transient simulation converge (per time step) in 5-7 iterations is reasonably good, thus having a setting of a maximum of 10 iterations per time step is OK. However, in your case I would be concerned about the size of the time step -- ensure that the simulation is actually converging after 10 iterations, not simply marching to the next time step because of the maximum iteration count you've imposed.

Regards,
ComputerGuy


All times are GMT -4. The time now is 21:39.