convergence criterium for unsteady 3D VOF

jack1980 · February 20, 2010, 03:29

Hello,

My objective is to calculate the drag coefficient on a free-surface ship. I would like to do this on three grids (coarse, medium, fine) and make a Richardson Extrapolation.

So now I get a time-history of the cd for each grid. I am wondering what would be the best convergence criterium? How do I proceed to find an appropiate and comparable cd for each grid? Where could I find information on this subject?

Thank you very much!

vmeertens · February 28, 2010, 06:49

Hi,

I'm doing the same research as you. I have to calculate the lift and drag on a speedboat using VOF. I have some results but i'm not sure if they are 100% correct.
If you want i can send you how i did the calculations. Maybe we can compare them to see if it's correct.

Vincent

jack1980 · February 28, 2010, 09:04

Great, I've sent you an email.

February 20, 2010, 03:29	convergence criterium for unsteady 3D VOF	#1
jack1980 Senior Member Jouke de Baar Join Date: Oct 2009 Posts: 127 Rep Power: 16	Hello, My objective is to calculate the drag coefficient on a free-surface ship. I would like to do this on three grids (coarse, medium, fine) and make a Richardson Extrapolation. So now I get a time-history of the cd for each grid. I am wondering what would be the best convergence criterium? How do I proceed to find an appropiate and comparable cd for each grid? Where could I find information on this subject? Thank you very much!

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February 28, 2010, 06:49		#2
vmeertens Member Vincent Meertens Join Date: Sep 2009 Location: Belgium Posts: 41 Rep Power: 16	Hi, I'm doing the same research as you. I have to calculate the lift and drag on a speedboat using VOF. I have some results but i'm not sure if they are 100% correct. If you want i can send you how i did the calculations. Maybe we can compare them to see if it's correct. Vincent

February 28, 2010, 09:04		#3
jack1980 Senior Member Jouke de Baar Join Date: Oct 2009 Posts: 127 Rep Power: 16	Great, I've sent you an email.