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

simpleFoam "Floating point exception" issues

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

Like Tree1Likes
  • 1 Post By piu58

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   August 10, 2021, 07:50
Question simpleFoam "Floating point exception" issues
  #1
New Member
 
Jo
Join Date: Aug 2021
Posts: 3
Rep Power: 2
hesed is on a distinguished road
Hi, I'm a student studying on CFD these days, and I've spent an amount of time trying to solve an error.

I'll upload the full log file, so you might be able to check if you need it.


------Error Message Begins--------

Time = 2.96

DILUPBiCG: Solving for Ux, Initial residual = 0.388057, Final residual = 0.0111543, No Iterations 61
DILUPBiCG: Solving for Uy, Initial residual = 0.461342, Final residual = 0.00384607, No Iterations 57
DICPCG: Solving for p, Initial residual = 0.999999, Final residual = 129029, No Iterations 1000
time step continuity errors : sum local = 4.41946e+103, global = -2.9527e+96, cumulative = -2.9527e+96
smoothSolver: Solving for nuTilda, Initial residual = 5.41952e-07, Final residual = 3.47411e-12, No Iterations 2
bounding nuTilda, min: -7.70956e+07 max: 1.53879e+09 average: 1.69814e+06
ExecutionTime = 1.5 s ClockTime = 1 s

Time = 3

#0 Foam::error:rintStack(Foam::Ostream&) at ??:?
#1 Foam::sigFpe::sigHandler(int) at ??:?
#2 ? in /lib/x86_64-linux-gnu/libpthread.so.0
#3 Foam::scalarProduct<double, double>::type Foam::sumProd<double>(Foam::UList<double> const&, Foam::UList<double> const&) at ??:?
#4 Foam::PBiCG::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const at ??:?
#5 Foam::fvMatrix<Foam::Vector<double> >::solveSegregated(Foam::dictionary const&) at ??:?
#6 Foam::fvMatrix<Foam::Vector<double> >::solveSegregatedOrCoupled(Foam::dictionary const&) at ??:?
#7 Foam::fvMesh::solve(Foam::fvMatrix<Foam::Vector<do uble> >&, Foam::dictionary const&) const at ??:?
#8 ? at ??:?
#9 __libc_start_main in /lib/x86_64-linux-gnu/libc.so.6
#10 ? at ??:?
Floating point exception

------Error Message Ends--------

I could check the pressure value not converging.

I've met this error before, and I was able to solve it by changing the solvers.
However, this time the error is not able to solve through these solvers.

I will add the files used for my CFD, however just for explanation the solvers that used to solve this problem were

solvers
{
p
{
solver PCG;
preconditioner DIC;
tolerance 1e-06;
relTol 0 .1;
}

U
{
solver PBiCG;
preconditioner DILU;
tolerance 1e-08;
relTol 0.1;
}

nuTilda
{
solver smoothSolver;
smoother DILU;
nSweeps 2;
tolerance 1e-08;
relTol 0.1;
}
}


But it doesn't seem to help anymore.



p.s. I couldn't upload my files due to file size limit. Instead if you need, you would be able to check the files that I used through the link following.

https://drive.google.com/drive/folde...rk?usp=sharing



Thank you very much for your help
Attached Files
File Type: txt log.txt (48.6 KB, 0 views)
hesed is offline   Reply With Quote

Old   August 10, 2021, 07:52
Default
  #2
Senior Member
 
piu58's Avatar
 
Uwe Pilz
Join Date: Feb 2017
Location: Leipzig, Germany
Posts: 727
Rep Power: 13
piu58 is on a distinguished road
Lok what happens with your pressuer:

Code:
DICPCG: Solving for p, Initial residual = 0.999999, Final residual = 129029, No Iterations 1000
time step continuity errors : sum local = 4.41946e+103, global = -2.9527e+96, cumulative = -2.9527e+96
Mostly, b.c. are wrong in such cases.
hesed likes this.
__________________
Uwe Pilz
--
Die der Hauptbewegung überlagerte Schwankungsbewegung ist in ihren Einzelheiten so hoffnungslos kompliziert, daß ihre theoretische Berechnung aussichtslos erscheint. (Hermann Schlichting, 1950)
piu58 is offline   Reply With Quote

Old   August 10, 2021, 22:08
Smile
  #3
New Member
 
Jo
Join Date: Aug 2021
Posts: 3
Rep Power: 2
hesed is on a distinguished road
Quote:
Originally Posted by piu58 View Post
Lok what happens with your pressuer:

Code:
DICPCG: Solving for p, Initial residual = 0.999999, Final residual = 129029, No Iterations 1000
time step continuity errors : sum local = 4.41946e+103, global = -2.9527e+96, cumulative = -2.9527e+96
Mostly, b.c. are wrong in such cases.
Thank you Mr. Pilz. I should check my b.c. and try again.

Have a nice day!
hesed is offline   Reply With Quote

Old   August 10, 2021, 22:24
Default
  #4
New Member
 
Jo
Join Date: Aug 2021
Posts: 3
Rep Power: 2
hesed is on a distinguished road
I was able to solve the problem by increasing the

"internalField", "freestreamValue" values of the

"nuTilda" file.

I am not sure how this worked out, but seems like it is related with the "SpalartAllmaras" RAS model.

Hope this might help anyone else having the same problem with me

==(edit)==

Found out Mr. Pilz was correct!

The B.C. for nuTilda was wrong. Checking out about Spalar Allmaras model at Wikipedia might help
https://en.wikipedia.org/wiki/Spalar...rbulence_model

Last edited by hesed; August 10, 2021 at 23:14. Reason: adding information!
hesed is offline   Reply With Quote

Reply

Tags
floating point exception, simplefoam

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
Compressible flow solving - issues with "Floating point exception" Ben786 OpenFOAM Running, Solving & CFD 3 August 8, 2021 10:31
Floating point exception using simplefoam sibo OpenFOAM Running, Solving & CFD 7 February 24, 2017 11:38
[Gmsh] Gmsh and samplesurface touf OpenFOAM Meshing & Mesh Conversion 2 December 10, 2007 02:27
Stagnation point and other issues Freeman FLUENT 0 December 12, 2005 15:16
CFX4.3 -build analysis form Chie Min CFX 5 July 12, 2001 23:19


All times are GMT -4. The time now is 02:09.