CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Running, Solving & CFD

Crash while solving lagrangian cloud

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   January 7, 2015, 09:52
Default Crash while solving lagrangian cloud
  #1
New Member
 
Werner
Join Date: Apr 2014
Posts: 19
Rep Power: 10
Polli is on a distinguished road
I use a modified steadycompressibleMRFFoam out of OpenFOAM extend 3.1 and combined it with the coalCombustionCase to fill in the particle movement into the steadycompressibleMRFFoam. The simulation has a problem while solving the particle cloud. It does not crash and stops but the simulation never ends solving the cloud and begins to hang. There is no error message, it only take more than days for one iteration at the particles. Normally it takes 2 seconds to solve the cloud. There are no problem with the flow field, i insert the particles in the stady state flow filed.
I tried many different things, like reducing the timestep, meshing the surface more exactly and things like that.
Do anybody know a possible solution for this problem?
Polli is offline   Reply With Quote

Old   January 8, 2015, 16:49
Default
  #2
Senior Member
 
Join Date: Jan 2010
Location: Stuttgart
Posts: 150
Rep Power: 14
Chrisi1984 is on a distinguished road
Hi Polly,

are you using "rebound" as wall interaction? In case you do so, the reason might be some bad quality in the mesh near to the wall.

For lagrangian simulations the mesh check should include an additional option:

checkMesh -allGeometry

Check the result from that analysis regarding "face tet" errors. Those "face tet" errors might be the reason for your "endless loop".

Kind regards
Chrisi
Chrisi1984 is offline   Reply With Quote

Old   January 9, 2015, 07:59
Default
  #3
New Member
 
Werner
Join Date: Apr 2014
Posts: 19
Rep Power: 10
Polli is on a distinguished road
Thank you for your input! I will check this. But one question, in wich line can i see if the face tet is ok or not. In the checkMesh - allGeometry i cant find a output which says face tet ok or not
Polli is offline   Reply With Quote

Old   January 9, 2015, 13:48
Default
  #4
Senior Member
 
Join Date: Jan 2010
Location: Stuttgart
Posts: 150
Rep Power: 14
Chrisi1984 is on a distinguished road
Hello,

this is a part of the output of checkMesh -allGemetry
Quote:
Checking geometry...
Overall domain bounding box (-0.0992995958 -1.00600017 -0.0992995271) (0.0992943162 0.205000025 0.0992996263)
Mesh (non-empty, non-wedge) directions (1 1 1)
Mesh (non-empty) directions (1 1 1)
Boundary openness (5.29574358e-17 -5.49843007e-17 1.75436041e-16) OK.
Max cell openness = 3.17555515e-16 OK.
Max aspect ratio = 9.68193754 OK.
Minumum face area = 3.52951045e-08. Maximum face area = 2.4132503e-05. Face area magnitudes OK.
Min volume = 6.03259587e-12. Max volume = 7.03459743e-08. Total volume = 0.0126674936. Cell volumes OK.
Mesh non-orthogonality Max: 74.3872277 average: 15.458555
*Number of severely non-orthogonal faces: 1.
Non-orthogonality check OK.
<<Writing 1 non-orthogonal faces to set nonOrthoFaces
Face pyramids OK.
Max skewness = 0.961890176 OK.
Coupled point location match (average 0) OK.
Face tets OK.
Min/max edge length = 0.000193831119 0.00775369872 OK.
All angles in faces OK.
Face flatness (1 = flat, 0 = butterfly) : average = 0.999989587 min = 0.987503483
All face flatness OK.
Cell determinant (wellposedness) : minimum: 0 average: 3.06790921
***Cells with small determinant found, number of cells: 557
<<Writing 557 under-determined cells to set underdeterminedCells
Concave cell check OK.

Failed 1 mesh checks.
There in you can read "Face tets OK".

Can you please check that again for your case.
Chrisi1984 is offline   Reply With Quote

Old   September 29, 2022, 04:51
Default
  #5
Senior Member
 
Join Date: Dec 2019
Location: Cologne, Germany
Posts: 306
Rep Power: 6
geth03 is on a distinguished road
Quote:
Originally Posted by Chrisi1984 View Post
Hello,

this is a part of the output of checkMesh -allGemetry


There in you can read "Face tets OK".

Can you please check that again for your case.
is there any workaround in case that face tets is not ok?
geth03 is offline   Reply With Quote

Reply

Tags
lagrange, mrf, particle, particle cloud

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
simpleFoam error - "Floating point exception" mbcx4jc2 OpenFOAM Running, Solving & CFD 12 August 4, 2015 03:20
Moving mesh Niklas Wikstrom (Wikstrom) OpenFOAM Running, Solving & CFD 122 June 15, 2014 07:20
Unstabil Simulation with chtMultiRegionFoam mbay101 OpenFOAM Running, Solving & CFD 13 December 28, 2013 14:12
calculation stops after few time steps sivakumar OpenFOAM Running, Solving & CFD 7 March 17, 2013 07:37
Could anybody help me see this error and give help liugx212 OpenFOAM Running, Solving & CFD 3 January 4, 2006 19:07


All times are GMT -4. The time now is 12:05.