[student666]

Hi,

I'm trying to run a MRF incompressible case in order to get suction pression at inlet patches cause by a fan.

My case is very simple, it is:

• incompressible
• steady state
• laminar (the I'll switch to turbulent)
• two inlets
• one outlet
• MRF zone (angular velocity fixed)

I set the following BC's:
U

boundaryField
{

    walls
    {
        type            noSlip;
    }

    blades
    {
        type            movingWallVelocity;
        value           uniform (0 0 0);
    }

    inletSx
    {
        type            pressureInletOutletVelocity;
        value           $internalField;//uniform (0 0 0);
    }
    inletDx
    {
        type            pressureInletOutletVelocity;
        value           $internalField;//uniform (0 0 0);
    }

    outlet
    {
            type            zeroGradient;
    }

}

p

boundaryField
{

    inletSx
    {
        type            totalPressure;
        p0            $internalField;
    }
    inletDx
    {
        type            totalPressure;
        p0            $internalField;
    }

    outlet
    {
        type            fixedValue;
        value           uniform 0;
    }

    walls
    {
        type            zeroGradient;
    }
    blades
    {
        type            zeroGradient;
    }
}

but I get pressure values at inlets near to zero. So I think that totalPressure BC's constrain its value.


I switched to zeroGradient for inlets, but as expected simulation blown up.


How can I set up properly my case?


Thanks.

[student666]

I add a picture of the case

[rcastilla]

What is the value of the $internalField for p?

[student666]

Originally Posted by rcastilla

What is the value of the $internalField for p?

I set all to 0 as it's incompressible

[brammekeuh987]

Hi M.C.

I'm having exactly the same problem.
I noticed that when I add the MRFproperties dict to my constant folder, my inlet BC's get overwritten by uniform (0 0 0) value in the first time step.
Originally the inlet condition was set to: fixedValue; value uniform (1 0 0);

Have you already solved this problem?

[brammekeuh987]

Hi M.C.

I found the error I had.

In the MRFproperties they ask for patches which don't rotate with the MRFzone.
First I thought that this only involves patches which are in the cellzone. I included the patches which were also present in the mesh, but not in the rotating cellZone and this solved my problem.

Regards
B.