[lreid]

Hi all,

I am having a some difficulty troubleshooting an error and am hoping someone would be able to give some here can help. I have provided the details of the case below.

[0] #0  Foam::error::printStack(Foam::Ostream&) at ??:?
[0] #1  Foam::sigFpe::sigHandler(int) at ??:?
[0] #2  ? in /lib/x86_64-linux-gnu/libpthread.so.0
[0] #3  Foam::multiply(Foam::Field<double>&, Foam::UList<double> const&, Foam::UList<double> const&) at ??:?
[0] #4  Foam::tmp<Foam::DimensionedField<double, Foam::volMesh> > Foam::operator*<Foam::volMesh>(Foam::DimensionedField<double, Foam::volMesh> const&, Foam::DimensionedField<double, Foam::volMesh> const&) at ??:?
[0] #5  Foam::RASModels::kOmega<Foam::IncompressibleTurbulenceModel<Foam::transportModel> >::correct() at ??:?
[0] #6  ? in /usr/lib/openfoam/openfoam2006/platforms/linux64GccDPInt32Opt/bin/pimpleFoam
[0] #7  __libc_start_main in /lib/x86_64-linux-gnu/libc.so.6
[0] #8  ? in /usr/lib/openfoam/openfoam2006/platforms/linux64GccDPInt32Opt/bin/pimpleFoam

Note: I have read the posts on debugging error like this and have narrowed down to lines 3 and 5, but uncertain of the solution.

CASE DETAILS

I am trying to simulate an unsteady oscillatory airflow rate through an upper respiratory tract geometry. The geometry is meshed using snappyHexMesh with checkMesh output suggesting an OK mesh (checkMeshLog attached). This is solved using kOmega and pimpleFoam, I have attached my '0' and 'system' files for detail on set up.

BC at inlet:

p - zeroGradient
k - fixedValue
omega - fixedValue
U - {
type flowRateInletVelocity;
volumetricFlowRate
{
type sine;
frequency 0.266;
amplitude 0.0016;
scale 1;
level 0;
}
}

BC at outlet:

p - fixedValue; uniform 0;
k- zeroGradient
omega - zeroGradient
U - zeroGradient


Additional information on error

It appears when visualising the results, the flow changes direction (outlet to inlet) there is a spike in velocity at the outlet then the inlet (see velocity vectors in attached images). Also, there in a dramatic drop in timestep to maintain the Courant no < 0.5.

This is my first time posting so let me know if there's any other useful information I can provide. I tried to convey what is necessary.

I would really appreciate any help the forum has to offer as I have been stuck on this for months.

Cheers,
Luke