pisoFoam - Too high Courant Numbers

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

 December 30, 2014, 09:47 pisoFoam - Too high Courant Numbers #1 Member   Join Date: Dec 2014 Posts: 33 Rep Power: 2 Hi all, I want to simulate a 3d case where a flow in a channel with a square cross section passes a barrier. See the sketch below. It's my very first case after going through the tutorials So, I decided to use pisoFoam since I believe it's well suitable for my case. My problem is that I get incredible high Courant numbers so that my calculation crashes. I've put some info for you. I hope you guys can help me fvSolution: https://dl.dropboxusercontent.com/u/59780963/fvSolution fvSchemes: https://dl.dropboxusercontent.com/u/59780963/fvSchemes checkMesh: https://dl.dropboxusercontent.com/u/59780963/checkMesh And that's the error I get: Time = 0.025 Courant Number mean: 3.03546e+85 max: 1.06297e+89 smoothSolver: Solving for Uy, Initial residual = 1, Final residual = 1.44087e-15, No Iterations 1 #0 Foam::error:rintStack(Foam::Ostream&) at ??:? #1 Foam::sigFpe::sigHandler(int) at ??:? #2 in "/lib/x86_64-linux-gnu/libc.so.6" #3 Foam::GAMGSolver::scale(Foam::Field&, Foam::Field&, Foam::lduMatrix const&, Foam::FieldField const&, Foam::UPtrList const&, Foam::Field const&, unsigned char) const at ??:? #4 Foam::GAMGSolver::Vcycle(Foam::PtrList const&, Foam::Field&, Foam::Field const&, Foam::Field&, Foam::Field&, Foam::Field&, Foam::Field&, Foam::Field&, Foam::PtrList >&, Foam::PtrList >&, unsigned char) const at ??:? #5 Foam::GAMGSolver::solve(Foam::Field&, Foam::Field const&, unsigned char) const at ??:? #6 Foam::fvMatrix::solveSegregated(Foam::dict ionary const&) at ??:? #7 Foam::fvMatrix::solve(Foam::dictionary const&) at ??:? #8 Foam::fvMatrix::solve() at ??:? #9 at ??:? #10 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6" #11 at ??:? Floating point exception (core dumped)

 December 30, 2014, 13:32 #2 Senior Member     Hasan K.J. Join Date: Dec 2011 Location: Bristol, United Kingdom Posts: 181 Rep Power: 5 Hey, The easiest option is to use pimpleFoam where you can set the maximum courant number. If you want use pisoFoam, you need to reduce the time step (delta t) in order to reduce the courant number. Kind Regards, Hasan K.J __________________ "Real knowledge is to know the extent of one's ignorance." - Confucius

 Thread Tools Display Modes Linear Mode

 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 OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post Endel OpenFOAM 2 August 20, 2013 03:57 Philip OpenFOAM 4 May 31, 2011 06:25 erncyc OpenFOAM Running, Solving & CFD 1 March 24, 2011 12:00 David_010 OpenFOAM Running, Solving & CFD 0 January 20, 2011 06:21 Bo Busk Jensen Main CFD Forum 3 September 5, 2002 05:41

All times are GMT -4. The time now is 19:53.