convergence criterium for unsteady 3D VOF

jack1980 · February 20, 2010, 04:29

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, 07:49

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, 10:04

Great, I've sent you an email.

February 20, 2010, 04:29	convergence criterium for unsteady 3D VOF	#1
jack1980 Senior Member Jouke de Baar Join Date: Oct 2009 Posts: 127 Rep Power: 17	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!

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Convergence of CFX field in FSI analysis	nasdak	CFX	2	June 29, 2009 02:17
the criterium of convergence for the SIMPLE algo	Lam	Main CFD Forum	1	July 25, 2007 10:08
VOF model convergence	lana	FLUENT	11	October 1, 2005 06:23
VOF convergence	CFD Newbie	FLUENT	3	November 24, 2002 02:14
VOF Convergence Problems for Accelerating Oil Pans	A Witry	FLUENT	6	June 21, 2001 23:45

February 28, 2010, 07:49		#2
vmeertens Member Vincent Meertens Join Date: Sep 2009 Location: Belgium Posts: 41 Rep Power: 17	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, 10:04		#3
jack1980 Senior Member Jouke de Baar Join Date: Oct 2009 Posts: 127 Rep Power: 17	Great, I've sent you an email.