Time Steps gets smaller and smaller

titio · July 17, 2009, 13:28

Hi Foamers,

I am trying to model the flow of a complex fluid where extra tension terms can be significant. I am trying to do the simulations imposing a limit maximun value for the courant number, in this case 0.001, and from there estimate the time step. I am using PISO.

The simulations starts O.K, but then the time steps go down very fast. Is there any way of controlling the mininum time step. The maximum step can be controlled in the controlDict Dictionary, but not the minimum time step.

How I can do it?

Regards,

Titio

s.sivakumar · July 22, 2009, 08:19

Hi,
just have look User Guide page number U-62 (dam break) example,
here u can get answer for u r question.

may be i am wrong also!

good luck,
sivakumar

July 17, 2009, 13:28	Time Steps gets smaller and smaller	#1
titio Senior Member Antonio Martins Join Date: Mar 2009 Location: Porto, Porto, Portugal Posts: 112 Rep Power: 17	Hi Foamers, I am trying to model the flow of a complex fluid where extra tension terms can be significant. I am trying to do the simulations imposing a limit maximun value for the courant number, in this case 0.001, and from there estimate the time step. I am using PISO. The simulations starts O.K, but then the time steps go down very fast. Is there any way of controlling the mininum time step. The maximum step can be controlled in the controlDict Dictionary, but not the minimum time step. How I can do it? Regards, Titio

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July 22, 2009, 08:19		#2
s.sivakumar New Member sivakumar Join Date: May 2009 Posts: 12 Rep Power: 16	Hi, just have look User Guide page number U-62 (dam break) example, here u can get answer for u r question. may be i am wrong also! good luck, sivakumar