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-   -   Time step continuity errors (http://www.cfd-online.com/Forums/openfoam-solving/115661-time-step-continuity-errors.html)

am9109 April 4, 2013 05:53

Time step continuity errors
 
Hello everyone,

I'm currently trying to run sonicFoam but I get the following error, does anyone have an idea about what could be the source of this problem?

Thanks!


Starting time loop

Time = 1e-08

Courant Number mean: 0.00176125 max: 0.0405339
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
DILUPBiCG: Solving for Ux, Initial residual = 1, Final residual = 7.76785e-17, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 1, Final residual = 9.40551e-11, No Iterations 2
DILUPBiCG: Solving for e, Initial residual = 1, Final residual = 1.48183e-10, No Iterations 2
DILUPBiCG: Solving for p, Initial residual = 1, Final residual = 1.83804e-16, No Iterations 4
DILUPBiCG: Solving for p, Initial residual = 0.00157704, Final residual = 1.98549e-14, No Iterations 3
DILUPBiCG: Solving for p, Initial residual = 2.68957e-05, Final residual = 6.00475e-13, No Iterations 2
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 1.03078e-16, global = -1.2921e-17, cumulative = -1.2921e-17
DILUPBiCG: Solving for p, Initial residual = 0.00126998, Final residual = 5.04877e-15, No Iterations 3
DILUPBiCG: Solving for p, Initial residual = 1.58899e-05, Final residual = 2.60516e-13, No Iterations 2
DILUPBiCG: Solving for p, Initial residual = 3.59162e-07, Final residual = 5.96198e-15, No Iterations 2
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
time step continuity errors : sum local = 9.92037e-17, global = -1.59358e-17, cumulative = -2.88568e-17
#0 Foam::error::printStack(Foam::Ostream&) at ??:?
#1 Foam::sigFpe::sigHandler(int) at ??:?
#2 Uninterpreted:
#3 Foam::divide(Foam::Field<double>&, Foam::UList<double> const&, Foam::UList<double> const&) at ??:?
#4 void Foam::divide<Foam::fvPatchField, Foam::volMesh>(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh>&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) at ??:?
#5 Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > Foam::operator/<Foam::fvPatchField, Foam::volMesh>(Foam::tmp<Foam::GeometricField<doub le, Foam::fvPatchField, Foam::volMesh> > const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) at ??:?
#6 Foam::compressible::RASModels::SpalartAllmaras::ch i() const at ??:?
#7 Foam::compressible::RASModels::SpalartAllmaras::co rrect() at ??:?
#8
at ??:?
#9 __libc_start_main in "/lib/i386-linux-gnu/libc.so.6"
#10
at ??:?

erichu April 4, 2013 07:23

It looks to me like div by zero in the turbulence model. Maybe try to change relaxation factors. So far I've never used a transient solver in OpenFOAM but Initial residual 0 for rho looks confusing to me.

giovanidiniz June 26, 2013 09:05

am9109,

I've been trying to setup a propeller in OF using pimpleDyMFoam and I faced the same error message you did.

What I had to do to was to adjust the initial deltaT in my controlDict and allow the solver to adjust it to control the Courant number using
"adjustTimeStep yes".

Not sure if it will help, but it might be worthing to give it a shot.

Hope it helps.

Cheers!

--
Giovani


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