# Open boundary condition for VOF in CFX

 Register Blogs Members List Search Today's Posts Mark Forums Read

 June 4, 2007, 06:17 Open boundary condition for VOF in CFX #1 Zhihua Xie Guest   Posts: n/a Dear all, I am using CFX for modeling the transient free surface flow, but I have a problem if I specify the open boundary condition for the domain. In CFX, you must specify the value of volume of fraction for each phase, nevertheless, you don't actually know the exact value of the volume of fraction in a transient case. How can I do that if I have to specify an open boundary condtion or can CFX specify a zero-gradient for fraction? It will be grateful if you can give me any further suggestions and thank you very much for your attention! Cheers, Zhihua

 June 4, 2007, 10:37 Re: Open boundary condition for VOF in CFX #2 Joe Guest   Posts: n/a Place the BCs where the VF is known a priori. If this is not possible you may have to calculate the BC hydrostatic pressure profile on the fly.

 June 4, 2007, 10:48 Re: Open boundary condition for VOF in CFX #3 Zhihua Xie Guest   Posts: n/a Thanks for your response. It is easy if the VF is known a priori. I t is possible to calculate the hydrostatic pressure if the BC is on the right of a 2D domain, but if the BC is on the top, how can I specify it? As a transient case, it will be complicated if calculating the hydrostatic pressure every time step. Anyway, thanks for your advice and I also wonder how to specify the zero-gradient for VF at the boundary. Does anyone have some further suggestion? Thanks.

 Thread Tools Display Modes Linear Mode

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post Saturn CFX 45 February 8, 2016 05:42 jannnesss CFX 5 February 25, 2011 17:24 radon CFX 0 November 23, 2010 05:24 CFD XUE FLUENT 0 July 8, 2010 06:49 bearcharge Main CFD Forum 0 May 14, 2010 11:32

All times are GMT -4. The time now is 21:19.