# pressure outlet problem

 User Name Remember Me Password
 Register Blogs Members List Search Today's Posts Mark Forums Read

 LinkBack Thread Tools Display Modes
 October 29, 2003, 07:24 pressure outlet problem #1 chanchala Guest   Posts: n/a Hi, I have a swirl inducing pipe and I'm simulating a 1.5m/s water flow through this pipe (100mm length pipe). I find that I'm getting a sudden change in pressure and tangential velocity at the exit where I've specified press. outlet BC with zero pressure. The tangential velocity which is high upto 1mm before the outlet suddenly drops and the press. drop also suddenly increases. I read somewhere that when you have swirling flow through an outlet, if you specify a constant pressure, the results won't be good because a change in pressure across the cross-section is required to provide the necessary centrifugal forces for the swirling flow. Is this the reason for the discrepancy? Does anyone know how I could fix this? At the moment I've simply extended the pipe beyond the point where I require results so that this affects somewhere I'm not concerned with. thanks in advance!

 October 31, 2003, 02:57 Re: pressure outlet problem #2 Conny Larsson Guest   Posts: n/a With a swirling flow you have a pressure gradient in radial direction in the pipe. When you enforce a constant pressure at the outlet the flow must adapt to this by decreasing the tangential velocity. You can try to use the "radial equilibrium pressure distribution" option for the pressure outlet. This should solve the problem. Conny L

 November 5, 2003, 07:59 Re: pressure outlet problem #3 chanchala Guest   Posts: n/a Hi, Thanks for the suggestion. I've tried this and it doesn't help. I still have the same problems. I guess I'll stick to extending the length for now! cheers

 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 Eric CFX 7 May 23, 2014 08:13 CoG STAR-CCM+ 4 June 9, 2010 21:47 emueller CFX 0 May 5, 2009 11:08 Antech Main CFD Forum 0 April 25, 2006 02:15 raivish CFX 0 January 6, 2006 09:47

All times are GMT -4. The time now is 10:08.

 Contact Us - CFD Online - Top