CFD Online Discussion Forums - problem with p_rgh BC and recirculation inside my domain

Hi everybody,

I'm trying to replicate a wind tunnel experiment by simulating the propagation of Helium in a building model using OF 2.1.1 and the firefoam solver.

My problem consist of an inlet source from which an air/helium mixture enter the fluid domain with a specified velocity profile and an outlet which should represent the ambient air.

I use the homogeneousDynOneEqEddymodel. Everything is desactivated in firefoam except the specie transport equations and I use the thermoType hsPsiMixtureThermo<multiComponentMixture<constGasT hermoPhysics>>.

I have read many posts here about p_rgh saying that totalPressure should be used for atmospheric BC and buyoantPressure everywhere else and everything works fine except that most of my mixture stay inside the domain. The flow only exit the domain at the bottom of the sides patches and nothing cross the top BC.

I'm quite new to OF and i'm a litte bit loss between all the BC availables. I have already dig into the source code and found many interesting things but can't find a way to get it working.

fixedValue for the outlet give me the same result whereas specifying a gradient BC (zeroGradient, buyoantPressure or fixedFluxPressure) let the fluid get out but gives a wrong field as expected since the pressure is specified nowhere. OutletInlet seems a good choice for me but it crash the calculation.

Any advice ?

Thanks in advance for your answers.

0/p_rgh

Code:

dimensions      [1 -1 -2 0 0 0 0];



internalField   uniform 101325;



boundaryField

{

    walls

    {

        type            buoyantPressure;

        value           $internalField;

    }

    inlet

    {

        type            buoyantPressure;

        value           $internalField;

    }

    pressure_outlets

      {

        type            totalPressure;

        p0              $internalField;

        U               U;

        phi             phi;

        rho             rho;

        psi             none;

        gamma           0;

        value           $internalField;

      }

}

0/U

Code:

dimensions      [0 1 -1 0 0 0 0];



internalField   uniform (0 0 0);



boundaryField

{

    walls

    {   

        type            fixedValue;

        value           uniform (0 0 0);

    }

    inlet

    {

        type            timeVaryingMappedFixedValue;

        setAverage      off;

    }

    pressure_outlets

    {

        type            pressureInletOutletVelocity;

        value           uniform (0 0 0);

        phi             phi;

    }

}

http://img15.hostingpics.net/thumbs/...9LESOF0553.png