[zordiack]

Hi, I've been wondering what is the correct velocity boundary condition to use for a rotating mesh? My case is a centrifugal fan which has a wall patch for the rotor blades. I'm moving the mesh (all cells in one cellZone) using the following dynamicMeshDict:

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2.2.2                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    location    "constant";
    object      dynamicMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dynamicFvMesh   solidBodyMotionFvMesh;

motionSolverLibs ( "libfvMotionSolvers.so" );

solidBodyMotionFvMeshCoeffs
{
    cellZone        rotor;

    solidBodyMotionFunction  rotatingMotion;
    rotatingMotionCoeffs
    {
        origin      (0 0 0);
        axis        (0 1 0);
        omega       50; // rad/s
    }
}

Which one should I use for the velocity boundary condition on the rotor patch?

        rotor_scale_solid
        {
            type fixedValue;
            value uniform ( 0 0 0);
        }

(the following is used in the propeller tutorial, but it doesn't make any sense to me to use movingWallVelocity for a rotating wall)

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

        rotor_scale_solid
        {
            type rotatingWallVelocity;
            origin (0 0 0);
            axis (0 1 0);
            omega 50;
        }

I would be really grateful if someone could point me in the right direction.

[fedvasu]

I hope by now you have figured it out, but if you are using OF-2.1 or above there is a tutorial case $FOAM_TUTORIALS/incompressible/pimpleDyMFoam/propellor

where propellor has movingWallVelocity value(0 0 0), I too am working on rotating machinery problem with pimpleDyMFoam I use movingwall 0.

The motion of fan has to be captured with AMI mesh regions and you must specify the rotating velocity in constant/dynamicMeshDict.

there are other ways to model this kind of problem but I am not well-versed in them.

[ChristianR1988]

hey!i am also busy with a rotorating blade within an static casing.i also use movingwallvelocity (0 0 0) for the blade-wall and fixedvalue (0 0 0) for the casing...but i just use ami for the cyclic boundaries...