CFD Online Logo CFD Online URL
Home > Forums > OpenFOAM Running, Solving & CFD

Increasing Square Cavity mesh to 100x100 causes crash. Why?

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

LinkBack Thread Tools Display Modes
Old   July 5, 2014, 06:13
Default Increasing Square Cavity mesh to 100x100 causes crash. Why?
New Member
Join Date: Jul 2014
Posts: 5
Rep Power: 3
Tom717 is on a distinguished road
Hi, I am a beginner with OpenFOAM and CFD in general.

I am experimenting with the first tutorial, the square cavity. For my first modifications I edited the mesh size. Changing from 20x20 to 40x40 caused no problem. However if I edit blockmeshdict to give me a 100x100 mesh then icoFoam crashes.

I get this:

Courant Number mean: 5.32474e+87 max: 2.58355e+89
#0  Foam::error::printStack(Foam::Ostream&) at ??:?
#1  Foam::sigFpe::sigHandler(int) at ??:?
#2   in "/lib/x86_64-linux-gnu/"
#3  Foam::symGaussSeidelSmoother::smooth(Foam::word const&, Foam::Field<double>&, Foam::lduMatrix const&, Foam::Field<double> const&, Foam::FieldField<Foam::Field, double> const&, Foam::UPtrList<Foam::lduInterfaceField const> const&, unsigned char, int) at ??:?
#4  Foam::symGaussSeidelSmoother::smooth(Foam::Field<double>&, Foam::Field<double> const&, unsigned char, int) const at ??:?
#5  Foam::smoothSolver::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const at ??:?
 at ??:?
 at ??:?
 at ??:?
 at ??:?
#10  __libc_start_main in "/lib/x86_64-linux-gnu/"
 at ??:?
Floating point exception (core dumped)
Can someone explain what is going wrong?


Last edited by wyldckat; July 6, 2014 at 05:17. Reason: Added [CODE][/CODE]
Tom717 is offline   Reply With Quote

Old   July 6, 2014, 05:23
Super Moderator
Bruno Santos
Join Date: Mar 2009
Location: Lisbon, Portugal
Posts: 8,659
Blog Entries: 34
Rep Power: 87
wyldckat is just really nicewyldckat is just really nicewyldckat is just really nicewyldckat is just really nice
Greetings Tom,

Notice this at the top of the output you've given?
Originally Posted by Tom717 View Post
Courant Number mean: 5.32474e+87 max: 2.58355e+89
The Courant Number should not go over 1.0, otherwise it will likely lead to a divergence and eventually crash.

I strongly suggest that you read the User Guide more carefully and take notes, because in the User Guide, section " Changing time and time step" it explains how the mesh resolution relates to the Courant Number and how the "deltaT" value should be adapted to the new mesh resolution.

If you did take this into account, you should have indicated what calculations you made and the "deltaT" value you used

Best regards,
wyldckat is offline   Reply With Quote


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
[ICEM] Hexa mesh, curve mesh setup, bunching law Anorky ANSYS Meshing & Geometry 4 November 12, 2014 01:27
Star CCM Overset Mesh Error (Rotating Turbine) thezack CD-adapco 3 December 11, 2013 04:09
[ICEM] Mirror Mesh | Delete duplicate mesh pythag0ra5 ANSYS Meshing & Geometry 6 November 19, 2013 08:35
[ICEM] Generating Mesh for STL Car in Windtunnel Simulation tommymoose ANSYS Meshing & Geometry 48 April 15, 2013 04:24
[ICEM] Problem making structural mesh on a surface froztbear ANSYS Meshing & Geometry 1 November 10, 2011 09:52

All times are GMT -4. The time now is 12:55.