[SylvainWang]

Hello, Foamers;

I just begin to use OpenFOAM to do my thesis. Since my problem is a compressible case, so I'd like to choose the rhoSimplecFoam solver to solve it. In the tutorial example offered in the rhoSimplecFoam solver, it gives a mass flowrate inlet condition and pressure outlet condition. However, in my case, it should be a total pressure inlet condition and pressure outlet condition. Problem comes as I changed the boundary conditions of U and P after 3 iterations. The error messages are as following:

#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::hePsiThermo<Foam:siThermo, Foam:ureMixture<Foam::sutherlandTransport<Foam:: species::thermo<Foam::hConstThermo<Foam:erfectGa s<Foam::specie> >, Foam::sensibleInternalEnergy> > > >::calculate() at ??:?
#4 Foam::hePsiThermo<Foam:siThermo, Foam:ureMixture<Foam::sutherlandTransport<Foam:: species::thermo<Foam::hConstThermo<Foam:erfectGa s<Foam::specie> >, Foam::sensibleInternalEnergy> > > >::correct() at ??:?
#5
at ??:?
#6 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#7
at ??:?
Floating point exception (core dumped)

and the new boundary conditions are
P

dimensions      [1 -1 -2 0 0 0 0];

internalField   uniform 100000;

boundaryField
{
    Default_Boundary_Region
    {
        type            zeroGradient;
    }
    inlet
    {
        type            totalPressure;
        U               U;
        phi             phi;
        rho             none;
        psi             none;
        gamma           1.4;
        p0              uniform 200000;
    }
    outlet
    {
        type            inletOutlet;
        phi             phi;
        inletValue      uniform 100000;
        value           uniform 100000;
    }
}

U

dimensions      [0 1 -1 0 0 0 0];

internalField   uniform (0 0 0);

boundaryField
{
    Default_Boundary_Region
    {
        type            fixedValue;
        value           uniform (0 0 0);
    }
    inlet
    {
        type            pressureInletVelocity;
        phi             phi;
        rho             rho;
        value           uniform (0 0 0);
    }
    outlet
    {
        type            pressureInletOutletVelocity;
        phi             phi;
        value           uniform (0 0 0);
    }
}

The version I used is 2.3.0, from the error message, it seems that the errors comes from the thermal properties. Nevertheless, we should not encounter any errors when just change the velocity inlet boundary condition to a total pressure boundary condition. Is there any problems in the modified boundary conditions?

Endless appreciation if any foamers can help. Sylvain

[tomf]

Hi Sylvain,

I think you should change your pressure boundary condition for the outlet to either a fixed static pressure or to outletInlet instead of inletOutlet. Look up their differences in the sourcecode!

Some hints:

$> cd $FOAM_SRC
$> find . -iname *inletoutlet*

If you have a supersonic outlet, zeroGradient or waveTransmissive may be better options.

You may also need to ramp your total pressure at the inlet over several iterations. I think some examples may be found on the forum.

Regards,
Tom