Time step size in VOF implicit

flow_CH · July 28, 2013, 01:50

Hello
I am new user in CFD.
I am modeling in VOF multiphase. In vof panel with activating the implicit, the courant number is deactive.
In this case, how can i define Time step size?
Thanks

Jim87 · July 28, 2013, 16:00

There is an universal equation in the users guide. In order to calculate your iteration to the timestep.

In my eyes you could test 3 cases (like 0,1 sec; 0,01 and 0,001). The residuals should give a first hint, if a time step size fits or not.

A general answer for your case isn't that easy. Maybe test 3 step sizes?

Here a discussion (maybe helpfull): http://www.cfd-online.com/Forums/flu...time-step.html

July 28, 2013, 01:50	Time step size in VOF implicit	#1
flow_CH Senior Member FHydro Join Date: Jan 2013 Posts: 197 Rep Power: 13	Hello I am new user in CFD. I am modeling in VOF multiphase. In vof panel with activating the implicit, the courant number is deactive. In this case, how can i define Time step size? Thanks

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July 28, 2013, 16:00		#2
Jim87 Member Stephan Langenberg Join Date: Sep 2011 Location: Germany Posts: 73 Rep Power: 14	There is an universal equation in the users guide. In order to calculate your iteration to the timestep. In my eyes you could test 3 cases (like 0,1 sec; 0,01 and 0,001). The residuals should give a first hint, if a time step size fits or not. A general answer for your case isn't that easy. Maybe test 3 step sizes? Here a discussion (maybe helpfull): http://www.cfd-online.com/Forums/flu...time-step.html