# free surface modelisation

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

 March 22, 2012, 04:19 free surface modelisation #1 New Member   Join Date: Feb 2012 Posts: 8 Rep Power: 7 Dear all, I am trying to model an open channel flow (free surface flow) in a pipe. The requirement is to obtain the 3D turbulent structure, including turbulence-driven secondary currents. I have tried innumerable strategies (combined inlet and seperate inlets....) with no luck in obtaining the expected results. In CCM+, I have defined a field function to fix the water level at the inlet (and used the same for initialization) but the free surface disapears.... Prob definition: Physics Models: -Multiphase VOF -Segregated Solver -Turbulent -> K-e realiz -Unsteady flow (Time step = 0.05s) BC's: -Combined Inlet: Velocity inlet [Magnitude = 0.5m/s)] -Outlet: Pressure Outlet -Turbulence specifications for Inlets and Outlets: TI = 10% Please have a look at the problem set up and sugest any change in strategy . Thank you

 March 25, 2012, 04:10 #2 Member   Join Date: May 2010 Posts: 38 Rep Power: 9 I think separate inlets is the best option, or maybe it will work using the flat wave model for combined inlet. How does the interface disappear?

 March 25, 2012, 14:36 #3 Member   Ryan Coe Join Date: Jun 2010 Location: Albuquerque, NM Posts: 98 Rep Power: 9 Have you applied any control to the water level at the outlet? __________________ Ryan

 April 1, 2012, 16:59 #4 Senior Member   Join Date: Oct 2009 Location: Germany Posts: 637 Rep Power: 15 The water level at the outlet should be a result of the behaviour within the domain. Anyway, the pressure at the outlet should be set according to the expected water level. Just a stupid question: Did you switch on gravity? Is the mesh fine enough?

April 10, 2012, 04:18
#5
New Member

Join Date: Feb 2012
Posts: 8
Rep Power: 7
yes i switch on gravity,
i put my air with a velocity of 0.5m/s, the same for water.
I attached a picture of the water level at the end of the simulation. I can't attache my report on the original format, my file exceeds the forum's limit . So i put the screenshots
Attached Images
 water level.jpg (20.6 KB, 39 views) report1.jpg (92.5 KB, 35 views) report2.jpg (91.8 KB, 19 views) report3.jpg (95.1 KB, 15 views) report4.jpg (92.8 KB, 12 views)

Last edited by hydraulic; April 10, 2012 at 04:40.

April 10, 2012, 04:21
#6
New Member

Join Date: Feb 2012
Posts: 8
Rep Power: 7
Thanks again,
Attached Images
 report5.jpg (97.3 KB, 10 views) report6.jpg (93.3 KB, 5 views) report7.jpg (93.9 KB, 5 views)

Last edited by hydraulic; April 10, 2012 at 04:43.

 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 mechovator CFX 24 April 8, 2011 00:41 samwh CFX 7 August 30, 2009 07:14 Luis CFX 8 May 29, 2007 18:13 Ryan Main CFD Forum 1 August 7, 2001 16:14 Elliot Schwartz Main CFD Forum 5 August 25, 1998 21:03

All times are GMT -4. The time now is 00:27.

 Contact Us - CFD Online - Privacy Statement - Top