CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Meshing & Mesh Conversion

[snappyHexMesh] SnappyHexMesh problems

Register Blogs Community New Posts Updated Threads Search

Like Tree25Likes
  • 3 Post By simonsg
  • 6 Post By danielbanos10
  • 10 Post By Dave ZL
  • 6 Post By Ship Designer

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   April 22, 2014, 00:20
Question SnappyHexMesh problems
  #1
New Member
 
Wang Jianhua
Join Date: Mar 2014
Posts: 9
Rep Power: 12
sjtuwjh is on a distinguished road
I am new to the OpenFoam and so does the Snappy. When I use the snappy to refine my mesh, here is the problem I got:
--> FOAM FATAL ERROR:
[1] cell 143882 of level 0 uses more than 8 points of equal or lower level
Points so far:8(1600 1601 1604 1605 1606 12690 12691 12692)
[1] From function hexRef8::setRefinement(const labelList&, polyTopoChange&) in file polyTopoChange/polyTopoChange/hexRef8.C at line 3500.
FOAM parallel run aborting
I don't how this happens and what can I do to solve this problem. So is there anyone who can help me find the reason? Looking forward to your kind request.
sjtuwjh is offline   Reply With Quote

Old   April 23, 2014, 04:47
Default
  #2
New Member
 
Simon Zhang
Join Date: Dec 2013
Posts: 12
Rep Power: 13
simonsg is on a distinguished road
Quote:
Originally Posted by sjtuwjh View Post
I am new to the OpenFoam and so does the Snappy. When I use the snappy to refine my mesh, here is the problem I got:
--> FOAM FATAL ERROR:
[1] cell 143882 of level 0 uses more than 8 points of equal or lower level
Points so far:8(1600 1601 1604 1605 1606 12690 12691 12692)
[1] From function hexRef8::setRefinement(const labelList&, polyTopoChange&) in file polyTopoChange/polyTopoChange/hexRef8.C at line 3500.
FOAM parallel run aborting
I don't how this happens and what can I do to solve this problem. So is there anyone who can help me find the reason? Looking forward to your kind request.
Hi Jianhua,

Please delete all the files under /constant/polyMesh except blockMeshDict, and then re-do the blockMesh and snappyHexMesh.

Regards,
Simon
peppino, Balzuka and zhan like this.
simonsg is offline   Reply With Quote

Old   May 23, 2014, 06:36
Default
  #3
New Member
 
eugenio l
Join Date: Feb 2014
Posts: 3
Rep Power: 12
iuginio is on a distinguished road
Hi everyone,

I keep having the same problem, especially when dealing with refinement level greater than 1. Deleting the file in ./constant/polyMesh doesn't help.

The cell whose referencing the error is always cell 1 of level 0

Code:
cell 1 of level 0 uses more than 8 points of equal or lower level
Points so far:8(1 2 6 7 26 27 31 32)
Thanks in advance for any useful help

Eugenio
iuginio is offline   Reply With Quote

Old   July 1, 2016, 08:31
Default
  #4
New Member
 
danielbanos10's Avatar
 
Join Date: Jun 2016
Location: Malaga, Spain
Posts: 15
Rep Power: 10
danielbanos10 is on a distinguished road
Hi,
I supose that's a bit late to post this, but maybe it will help someone.
I had the same error when I used snappy with a previously created blockmesh with mergePatchPairs.
The first step is to visualize where is that problem cell, using paraview you can find out it.
And my solution was to do a smaller refinement box, in order to have a distance from that patch to the box, and also reduce a little bit the difference between the sizes of the blockmesh merged patches.
Dave ZL, havref, kostnermo and 3 others like this.
danielbanos10 is offline   Reply With Quote

Old   April 10, 2017, 11:14
Default
  #5
New Member
 
Join Date: Oct 2014
Posts: 1
Rep Power: 0
Dave ZL is on a distinguished road
Quote:
Originally Posted by danielbanos10 View Post
Hi,
I supose that's a bit late to post this, but maybe it will help someone.
I had the same error when I used snappy with a previously created blockmesh with mergePatchPairs.
The first step is to visualize where is that problem cell, using paraview you can find out it.
And my solution was to do a smaller refinement box, in order to have a distance from that patch to the box, and also reduce a little bit the difference between the sizes of the blockmesh merged patches.
True!

I found out using a lower nCellsBetweenLevels (1 or 0 instead of 2) in the snappyHexMeshDict helps too (which has to do with the transition smoothness between the different levels of refinement).

Dave
reza2031, donQi, amuzeshi and 7 others like this.
Dave ZL is offline   Reply With Quote

Old   November 25, 2020, 19:49
Default snappyHexMesh aborts if background mesh was refined without level transition cells
  #6
Senior Member
 
Claudio Boezio
Join Date: May 2020
Location: Europe
Posts: 137
Rep Power: 7
Ship Designer is on a distinguished road
I just got the same error while trying to snap a surface into a background mesh previously refined with refineMesh. At first I thought that snappyHexMesh was aborted because it intersected a polyhedron cell with mor than 8 vertices. Upon investigation of the reported cell I noticed though that the incriminated cell was a hexahedron and also on the opposite end of the mesh, thus far from being intersected by the surface to be snapped. I then ran only one refinement with refineMesh and snappyHexMesh worked without errors to my surprise.

I've been using topoSet and refineMesh twice in a row to get two levels of refinement. This left no buffer cells between the refinement levels and is the likely cause of the problem. I changed the first topoSetDict to select a slightly larger cellSet as to leave at least one cell between the two refinement levels and after that snappyHexMesh ran without errors.

Cheers, Claudio
Ship Designer is offline   Reply With Quote

Reply

Tags
snappy hex mesh


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
[snappyHexMesh] Problems with coarse/unsnapped cells in snappyHexMesh scareneb OpenFOAM Meshing & Mesh Conversion 2 August 13, 2014 08:13
[snappyHexMesh] snappyHexMesh problems 1.5->1.6 grtabor OpenFOAM Meshing & Mesh Conversion 5 May 18, 2012 04:00
[snappyHexMesh] stitchMesh and snappyHexMesh gdbaldw OpenFOAM Meshing & Mesh Conversion 0 December 23, 2009 03:09
[snappyHexMesh] SnappyhexMesh and Symmetryplane bastil OpenFOAM Meshing & Mesh Conversion 10 October 7, 2008 18:07
[snappyHexMesh] SnappyHexMesh not generate mesh first time mavimo OpenFOAM Meshing & Mesh Conversion 4 August 26, 2008 08:08


All times are GMT -4. The time now is 16:35.