CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > CFX

tank sloshing overflow error

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   January 19, 2011, 23:34
Default tank sloshing overflow error
  #1
Member
 
Hamed
Join Date: Jun 2010
Posts: 43
Rep Power: 15
enghamed is on a distinguished road
I have modeled a recetangular tank with a unit thickness (2D) and runs well but when I change the mesh to cylinder tank (3D) with all the same conditions for the 2D, I get fatal overflow error!!!
why is this happening? what should I do?
enghamed is offline   Reply With Quote

Old   January 20, 2011, 04:19
Default
  #2
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,703
Rep Power: 143
ghorrocks is just really niceghorrocks is just really niceghorrocks is just really niceghorrocks is just really nice
Can you describe what you are doing a bit better?

But the problem is probably mesh quality.
ghorrocks is offline   Reply With Quote

Old   January 20, 2011, 20:38
Default
  #3
Member
 
Hamed
Join Date: Jun 2010
Posts: 43
Rep Power: 15
enghamed is on a distinguished road
I want to model water sloshing in a cylinder tank.
As a first attempt I modeled a rectangular tank with two faces of symetry and the top as open and the other three faces as wall. Defined the mesh displacment for the wall as x=Asinwt. It ran very good.
Now i change the goemetry with a cylindrecal tank and didn't change any settings, but now i get error of "Floating point exception: Overflow".
I have meshed the goemetry in ICEM with an o-grid.
any more details you need?
enghamed is offline   Reply With Quote

Old   January 21, 2011, 00:37
Default
  #4
Member
 
Hamed
Join Date: Jun 2010
Posts: 43
Rep Power: 15
enghamed is on a distinguished road
I now tried a 3D rectangular and agian got the overflow error.
It shouldn't be the quality of the mesh since now I have a complete square hex elements!
Have u got any idea what is going wrong?

regards
enghamed is offline   Reply With Quote

Old   January 21, 2011, 06:28
Default
  #5
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,703
Rep Power: 143
ghorrocks is just really niceghorrocks is just really niceghorrocks is just really niceghorrocks is just really nice
No idea what is wrong.

Add the physics into the model one step at a time. Does the 3D model work with a static mesh, but the initial free surface deformed somehow to start a motion? Does the model work with a motion of a small magnitude?
ghorrocks is offline   Reply With Quote

Old   June 24, 2011, 13:55
Default
  #6
New Member
 
Dijun Pan
Join Date: Jun 2011
Posts: 13
Rep Power: 14
zcesd47 is on a distinguished road
hi,enghamed
I am now modeling a case very similar to your one, the water sloshing in a rectangular tank, I use two domains one as water and the other as air, and applied the displacement sin(wt) to the walls of the tanks. initial condition for air domain volume fraction air= 1& volume fraction water =0. The contrast for water domain. But when I try to solve it, the solver terminate at the 1st timestep, the linear solution for U-mom V-mom and P-vol failed. I change my B.C and timesteps but doesn't help. Do you have any suggestions for my problem. Could you tell me how you set you interface and initial conditions. Very much appreciated.

Regards

Dijun
zcesd47 is offline   Reply With Quote

Old   June 25, 2011, 06:50
Default
  #7
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,703
Rep Power: 143
ghorrocks is just really niceghorrocks is just really niceghorrocks is just really niceghorrocks is just really nice
Do the tutorial free surface flow over a bump for ideas of how to set up and run free surface models.
ghorrocks is offline   Reply With Quote

Old   June 25, 2011, 13:19
Default
  #8
New Member
 
Dijun Pan
Join Date: Jun 2011
Posts: 13
Rep Power: 14
zcesd47 is on a distinguished road
Thank you . It seems that I define the Buoyancy ref. density as Water's density instead of air's.
zcesd47 is offline   Reply With Quote

Reply


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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Compile calcMassFlowC aurore OpenFOAM Programming & Development 13 March 23, 2018 07:43
nonNewtonian viscosity model mhassani OpenFOAM Programming & Development 5 January 7, 2013 09:27
Accessing phi from a fvPatchField at same patch johndeas OpenFOAM 1 September 13, 2010 20:23
attach/detach (valve opening/closing) phsieh2005 OpenFOAM Running, Solving & CFD 2 March 21, 2009 05:18
OpenFOAM on MinGW crosscompiler hosted on Linux allenzhao OpenFOAM Installation 127 January 30, 2009 19:08


All times are GMT -4. The time now is 05:14.