Global Courant Number of VOF

flatfoosie · August 14, 2009, 10:39

Hello,
I am using Fluent 6.3.26 to solve a VOF model about Air Pump, but I fall across a difficulty about how to set Variable Time Step Parameters only used in VOF model, thereinto the Global Courant Number I cann't confirm and I have not seen any article discussing its reasonable range, and I know the default is 2.
Now I want a larger Time Step Size which can assure convergence to consume fewer time, is it right that I change the default Global Courant Number 2 to 20 if 20 can also assure my model convergence.
I spent ten days to get a result with a computer of 4 CPU & 8G EMS memory & 32 bit WinXP, the Time Step Size I gave is 1e-5, but I feel it is too small and cost me too much time, I still have many types of Air Pump. How much time I will spend having them finished! My God!
Thanks for any reply!

flatfoosie · August 15, 2009, 23:41

No one answers me? No one knows how to confirm it?
I'm disappointed, very very disappointed..........

August 14, 2009, 10:39	Global Courant Number of VOF	#1
flatfoosie New Member Flatfoosie Join Date: May 2009 Posts: 3 Rep Power: 17	Hello, I am using Fluent 6.3.26 to solve a VOF model about Air Pump, but I fall across a difficulty about how to set Variable Time Step Parameters only used in VOF model, thereinto the Global Courant Number I cann't confirm and I have not seen any article discussing its reasonable range, and I know the default is 2. Now I want a larger Time Step Size which can assure convergence to consume fewer time, is it right that I change the default Global Courant Number 2 to 20 if 20 can also assure my model convergence. I spent ten days to get a result with a computer of 4 CPU & 8G EMS memory & 32 bit WinXP, the Time Step Size I gave is 1e-5, but I feel it is too small and cost me too much time, I still have many types of Air Pump. How much time I will spend having them finished! My God! Thanks for any reply! Last edited by flatfoosie; August 14, 2009 at 11:30.

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August 15, 2009, 23:41		#2
flatfoosie New Member Flatfoosie Join Date: May 2009 Posts: 3 Rep Power: 17	No one answers me? No one knows how to confirm it? I'm disappointed, very very disappointed..........