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

2D simpleFoam simulation gets stuck - no error - problem with boundaries?

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

Reply
 
LinkBack Thread Tools Display Modes
Old   July 13, 2011, 05:14
Default 2D simpleFoam simulation gets stuck - no error - problem with boundaries?
  #1
Senior Member
 
lore
Join Date: Mar 2010
Location: Italy
Posts: 463
Rep Power: 9
lovecraft22 is on a distinguished road
Send a message via Skype™ to lovecraft22
Hi all;
trying to run a simple 2D circular cylinder.

I have already run that but I got a 3D resulting field so I slightly changed the boundary conditions and now the simulation gets stuck without any error at:

Code:
Time = 1

smoothSolver:  Solving for Ux, Initial residual = 0.407396, Final residual = 0.0155929, No Iterations 3
smoothSolver:  Solving for Uy, Initial residual = 0.485038, Final residual = 0.0173646, No Iterations 3
What you think could be the problem?
Maybe something related to my boundaries?

Thank you!

Lorenzo

Last edited by lovecraft22; July 13, 2011 at 16:30.
lovecraft22 is offline   Reply With Quote

Old   July 13, 2011, 05:16
Default
  #2
Senior Member
 
lore
Join Date: Mar 2010
Location: Italy
Posts: 463
Rep Power: 9
lovecraft22 is on a distinguished road
Send a message via Skype™ to lovecraft22
Update: I think it blows up and I get a floating point excepion…

Any help would be really appreciated!
lovecraft22 is offline   Reply With Quote

Old   July 13, 2011, 05:37
Default
  #3
Member
 
The True
Join Date: Dec 2010
Posts: 80
Rep Power: 6
Eren10 is on a distinguished road
set-up normal files for BC , especially for U and p. I dont see why you are using complicates structure of the files, look to the tutorials
Eren10 is offline   Reply With Quote

Old   July 13, 2011, 07:32
Default
  #4
Senior Member
 
lore
Join Date: Mar 2010
Location: Italy
Posts: 463
Rep Power: 9
lovecraft22 is on a distinguished road
Send a message via Skype™ to lovecraft22
Thank you Eren.

What do you mean with "Complicate file structure"?
lovecraft22 is offline   Reply With Quote

Old   July 13, 2011, 12:59
Default
  #5
Senior Member
 
lore
Join Date: Mar 2010
Location: Italy
Posts: 463
Rep Power: 9
lovecraft22 is on a distinguished road
Send a message via Skype™ to lovecraft22
Ok, I simplified the boundary conditions for U and p (which I copied from the motorbike tutorial and that's why they were a little bit complicated).

Now, what should I set for the turbulence model (K-e) conditions?
lovecraft22 is offline   Reply With Quote

Old   July 13, 2011, 16:37
Default
  #6
Senior Member
 
lore
Join Date: Mar 2010
Location: Italy
Posts: 463
Rep Power: 9
lovecraft22 is on a distinguished road
Send a message via Skype™ to lovecraft22
Eventually I managed to solve the case but I got a 3D solution instead of a 2D one, as you can see from the pressure plot on the surface:


What may the problem be?

Thank you!
Attached Files
File Type: zip cilindro2D_2.zip (52.7 KB, 13 views)
lovecraft22 is offline   Reply With Quote

Old   July 14, 2011, 09:58
Default
  #7
Member
 
The True
Join Date: Dec 2010
Posts: 80
Rep Power: 6
Eren10 is on a distinguished road
you want to simulate a 2D, so x and y . In the z direction only a one cell is required. if we asume x y forms the circular shape of the cylinder, than the domains parallel to the x- y plane should be empty.
Eren10 is offline   Reply With Quote

Old   July 14, 2011, 10:14
Default
  #8
Senior Member
 
lore
Join Date: Mar 2010
Location: Italy
Posts: 463
Rep Power: 9
lovecraft22 is on a distinguished road
Send a message via Skype™ to lovecraft22
Tank you eren. If you look at my case directory you'll see that I already have only ove cell in z direction and both the planes perpendicular to the z-axis are already set as empty...
lovecraft22 is offline   Reply With Quote

Old   July 14, 2011, 10:28
Default
  #9
Member
 
The True
Join Date: Dec 2010
Posts: 80
Rep Power: 6
Eren10 is on a distinguished road
I have no experience with the openfoam's way of generating the object, I am using an other program for mesh. so I cant help you. But make the distance in the z direction very small. but if that is oke, make a paint figure of the inlet outlet conditions etc.. in 2D, than we can check the BC.
Eren10 is offline   Reply With Quote

Old   July 14, 2011, 12:05
Default
  #10
Senior Member
 
lore
Join Date: Mar 2010
Location: Italy
Posts: 463
Rep Power: 9
lovecraft22 is on a distinguished road
Send a message via Skype™ to lovecraft22
Inlet and outlet conditions (e.g. pressure) are perfectly 2D…
lovecraft22 is offline   Reply With Quote

Old   July 15, 2011, 13:51
Default
  #11
Senior Member
 
lore
Join Date: Mar 2010
Location: Italy
Posts: 463
Rep Power: 9
lovecraft22 is on a distinguished road
Send a message via Skype™ to lovecraft22
I think I'll open another topic for this problem, since it's quite different from the one I started this topic for.
lovecraft22 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
FSI TWO-WAY SIMULATION Smagmon CFX 1 March 6, 2009 14:24
Overflow problem in steady simulation ReeKo CFX 11 October 8, 2008 17:57
Tank simulation: Boundaries Humberto Avila FLUENT 2 May 17, 2006 14:18
Fire simulation using FDS from NIST Jens Main CFD Forum 1 January 22, 2004 02:53
3-D Contaminant Dispersal Simulation Apple L S Chan Main CFD Forum 1 December 23, 1998 11:06


All times are GMT -4. The time now is 09:52.