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

Dynamic mesh + grid adapt = Crash! (Files included

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

Reply
 
LinkBack Thread Tools Display Modes
Old   July 20, 2007, 07:43
Default Dynamic mesh + grid adapt = Crash! (Files included
  #1
BillH
Guest
 
Posts: n/a
Hi all,

I am having no luck trying to get dynamic mesh and grid adaptation working in even a trivial example.

I have set up a simple four sided 2D block with an inlet, outlet and two walls. Air enters the inlet at 1 m/s.
http://img181.imageshack.us/img181/4509/meshdv8.jpg

I have included a small square inclusion in the domain called "rod". Rod is driven to rotationally oscillate with a trivial DEFINE_CG_MOTION macro.

The idea of this test case is to test adaptation in conjunction with a dynamic mesh.

The case (as included in the zip file below) runs fine without adaptation turned on. I have tried to include adaptation in two ways:

a) Run for say 50 timesteps. Do a manual gradient adaptation on say the pressure gradient and then restart the run for another 50 timesteps. This immediately crashes the run with the following generic error message:

Error:
FLUENT received fatal signal (ACCESS_VIOLATION)
1. Note exact events leading to error.
2. Save case/data under new name.
3. Exit program and restart to continue.
4. Report error to your distributor.
Error Object: ()

(b) Turn on dynamic adaptation before stating the solve on say the pressure gradient. This runs fine until the first adaptation step, seems to complete the fist post-adaptation timestep and then crashes again with the above error.
http://img76.imageshack.us/img76/696...ergencebc8.jpg

I have tried a myriad of gradient based adaptation combinations on various variables but they all fail in exactly the same way.

This leads me to suspect that dynamic mesh and grid adaptation cannot be used concurrently but other fluent users (e.g. red lemon) have hinted that this should in fact be possible.

I would be grateful if anyone can give my any input on this problem. I have included a tiny zip file with the case files if anyone would like to re-run my problem. As I mentioned before, the case runs fine as is because adaptation is off. However, if adaptation is turned on in any form, dynamic or once off, the solve crashes.

Case files zip (350 kB): http://rapidshare.com/files/43981168...adapt.zip.html

Thanks!
  Reply With Quote

Old   July 20, 2007, 16:31
Default Re: Dynamic mesh + grid adapt = Crash! (Files incl
  #2
red lemon
Guest
 
Posts: n/a
Hi Adaption requires that hanging node grids are created. I dont think on reflection it is possible to remesh a hanging node grid. In same way you cant adapt a polyhedral or hexcore mesh. I'd need to check limitations on that in UG. cheers
  Reply With Quote

Old   July 22, 2007, 08:57
Default Re: Dynamic mesh + grid adapt = Crash! (Files incl
  #3
BillH
Guest
 
Posts: n/a
I thought about what you said about hanging node meshes and dynamic meshing being incompatible and it made sense.

I therefore switched from hanging node mesh adaptation to conformal mesh adaptation. Now it works perfectly!

So it seems that dynamic mesh and mesh adaptation can be used simultaneously but only if you use conformal adaptation, which is fine for my aplication.
  Reply With Quote

Old   July 22, 2007, 09:17
Default Re: Dynamic mesh + grid adapt = Crash! (Files incl
  #4
BillH
Guest
 
Posts: n/a
Strange. Repeated manual adaptation works fine, but automatic adaptation using the exact same adaptation settings hangs like in my first message.

Strange ....
  Reply With Quote

Old   July 24, 2007, 15:31
Default Re: Dynamic mesh + grid adapt = Crash! (Files incl
  #5
BillH
Guest
 
Posts: n/a
OK. I have got automatic mesh adaptation + dynamic remeshing working together. For the automatic mesh adaptation settings ONLY mark deforming tet/tri fluid zones as being adaptable under "controls".
  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
Moving mesh Niklas Wikstrom (Wikstrom) OpenFOAM Running, Solving & CFD 122 June 15, 2014 06:20
Dynamic mesh is not getting updated. cardio FLUENT 1 May 20, 2014 08:41
snappyHexMesh won't work - zeros everywhere! sc298 OpenFOAM Native Meshers: snappyHexMesh and Others 2 March 27, 2011 21:11
fluent add additional zones for the mesh file SSL FLUENT 2 January 26, 2008 12:55
Grid Quality and the Solution Faraz Main CFD Forum 4 January 10, 2000 19:18


All times are GMT -4. The time now is 06:10.