continuity convergence

hamid1 · July 20, 2012, 04:30

Hi,
do you know
how to fix convergence in continuity in modeling with vof (implicit)?

shk12345 · July 20, 2012, 05:24

Decrease the time step and try it.
Change grid.

shk

hamid1 · July 20, 2012, 05:37

thanks for reply, i decreased the time step .. it still oscillates .. Unfortunatly i can not increase the mesh .. or cahnge..
what about URF,
does changing URF, (radically decreasing it) leads to wrong results (even if reaching to convergence and low residuals) ?

flotus1 · July 20, 2012, 05:52

If "convergence" is achieved, it doesn't matter with which under-relaxation factor your simulation got there.

It will only take longer with low URF.

July 20, 2012, 04:30	continuity convergence	#1
hamid1 Senior Member hamid Join Date: Nov 2010 Posts: 185 Rep Power: 15	Hi, do you know how to fix convergence in continuity in modeling with vof (implicit)?

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July 20, 2012, 05:24		#2
shk12345 Senior Member shoeb khan Join Date: Nov 2011 Posts: 179 Rep Power: 14	Decrease the time step and try it. Change grid. shk

July 20, 2012, 05:37		#3
hamid1 Senior Member hamid Join Date: Nov 2010 Posts: 185 Rep Power: 15	thanks for reply, i decreased the time step .. it still oscillates .. Unfortunatly i can not increase the mesh .. or cahnge.. what about URF, does changing URF, (radically decreasing it) leads to wrong results (even if reaching to convergence and low residuals) ?

July 20, 2012, 05:52		#4
flotus1 Super Moderator Alex Join Date: Jun 2012 Location: Germany Posts: 3,399 Rep Power: 46	If "convergence" is achieved, it doesn't matter with which under-relaxation factor your simulation got there. It will only take longer with low URF.