CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > OpenFOAM

interFoam, problems with volume fraction conservation

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

Reply
 
LinkBack Thread Tools Display Modes
Old   October 12, 2009, 03:58
Default interFoam, problems with volume fraction conservation
  #1
New Member
 
jhegar
Join Date: Jun 2009
Posts: 4
Rep Power: 8
jorgehegar is on a distinguished road
Hello everybody!
I´m having problems with interFoam solver used in the new OpenFoam version 1.6.
From the first time step the liquid volum fraction starts to decrease, and that shouldn´t happen in my problem, until the water reachs the Outlet (that happens after 3-4 seconds of simulation).
With the same boundary conditions I obtained no problem with version 1.5. The liquid volume fraction was constant till the liquid come to the Outlet.
It seems like if there is somewhere some type of numeric problem.

My problem is a U-pipe that has enough water to full fill the horizontal part of the pipe.

Can someone help me with this tema? Do anyone know if they have change something by the numeric procedure of the new version?

Thank you very much for your help and time.
jorgehegar is offline   Reply With Quote

Old   October 12, 2009, 07:32
Default
  #2
Member
 
Jean-Peer Lorenz
Join Date: Mar 2009
Location: Rostock, Germany
Posts: 33
Rep Power: 8
jploz is on a distinguished road
Hi,

I do not understand your setup exactly. Could you provide some additional information about the case? Maybe a picture of the domain? I guess the amount of water remains equal while it moves towards to outlet?

Regards. Jean-Peer
jploz is offline   Reply With Quote

Old   October 12, 2009, 07:51
Default
  #3
New Member
 
jhegar
Join Date: Jun 2009
Posts: 4
Rep Power: 8
jorgehegar is on a distinguished road
U_pipe.JPGHi,
hear I attach a picture with the geometry boundaries of the problem.
Thanks.
jorgehegar is offline   Reply With Quote

Old   October 13, 2009, 04:18
Default
  #4
ngj
Senior Member
 
Niels Gjoel Jacobsen
Join Date: Mar 2009
Location: Deltares, Delft, The Netherlands
Posts: 1,660
Rep Power: 25
ngj will become famous soon enoughngj will become famous soon enough
Hi

I have read somewhere on the Forum that chaging from pd -> p makes the zeroGradient on p at walls erroneous, as you have a hydrostatic component, i.e. dp/dn differs from zero.
I am currently working in 1.6, hence could you see, if you can compute the hydrostatic pressure with no inflow in your setup without loosing any fluid?

Hope it helps,

Niels
ngj is offline   Reply With Quote

Old   October 15, 2009, 06:53
Exclamation interFoam no volume conservation in 1.6
  #5
New Member
 
Harald Swidersky
Join Date: Oct 2009
Location: Munich, Germany
Posts: 1
Rep Power: 0
harald.swi is on a distinguished road
Hello,

With Version 1.6 I observed also, that the volume fraction of liquid drops if I calculate a half filled bending over a longer time (4-10 s) until the liquid dissapeared completely. At the open ends of the bending I set u=0 m/s and P = 10e5 Pa respectively (-> zero flow). The hydrostatic pressure seems to be o.k.. The violation of the volume conservation does not appear if I use version 1.5 ! I would be glad, if someone knows what has been changed in the underlying solver or equations since 1.5.
harald.swi is offline   Reply With Quote

Reply

Thread Tools
Display Modes

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 Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Error message: Insufficient Catalogue Size Paresh Jain CFX 29 January 10, 2016 02:18
volume fraction in mixture model and VOF???? multiphase-flow FLUENT 4 August 7, 2014 10:35
CFX Solver Memory Error mike CFX 1 March 19, 2008 08:22
Problems with Volume Fraction Richard Pemberton CFX 1 May 27, 2001 10:49
help needed about phase change Yanhu Guo Main CFD Forum 4 January 24, 2001 00:16


All times are GMT -4. The time now is 09:51.