[BSengupta]

Hi everyone.


I wish to simulate a rotor with NACA0012 blades with 8 deg AOA and 0 deg cyclic pitch. The diameter is 0.78m. I used MRF with ggi interface between static and rotating interface. The freestream velocity is 15m/s in the positive X direction.


I am getting a very low-velocity zone at the end of the blade to ggi interface of the rotor. It seems there is a strong demarkation across ggi interface in the flowfield of U. I am sharing the the filed of U, p and rho.

(The figures in XZ plane are taken at Y=-0.2m)


Can anyone please give some insight to it.
Thank you

[tomf]

Hi,

I had similar issues when I forgot to add the AMI/ggi to the list of nonRotatingPatches in MRFProperties. So that might be the issue?

Regards,
Tom

[BSengupta]

Thanks a lot for your reply. I just wanted to ask that should I add both ggi patches connected to rotor and stator in the list of nonRotatingPatches.


My boundary file is:

4
(
    RotorGGI
    {
        type            ggi;
        nFaces          20200;
        startFace       14221862;
        rotationAxis    (0 0 1);
        nCopies         30;
        shadowPatch     StatorGGI;
        zone            RotorGGI_faces; 
        bridgeOverlap     true;
    }
    wall
    {
        type            wall;
        nFaces          107940;
        startFace       14242062;
    }
    farfield
    {
        type            patch;
        nFaces          4800;
        startFace       14350002;
    }
    StatorGGI
    {
        type            ggi;
        nFaces          6100;
        startFace       14354802;
        rotationAxis    (0 0 1);
        nCopies         30;
        shadowPatch     RotorGGI;
        zone            StatorGGI_faces; 
        bridgeOverlap     true;
    }
)

And my MRFZones file is (presently modified as you suugested):

1
(
    cellRegion0//rotor
    {
        // Fixed patches (by default they 'move' with the MRF zone)
        nonRotatingPatches (farfield);
        nonRotatingPatches (RotorGGI);
        nonRotatingPatches (StatorGGI);
         origin    origin [0 1 0 0 0 0 0]  (0 0 0);
        axis      axis   [0 0 0 0 0 0 0]  (0 0 -1);
        omega     omega  [0 0 -1 0 0 0 0] 333.3;
    }
)

Is it correct to add both RotorGGI and StatorGGI to nonRotatingPatches or I should only add StatorGGI.


Thank you.

[BSengupta]

I apologies for asking a foolish question. I just added StatorGGI, I thinking it it working.


Thank you.

[tomf]

Hi,

I guess you have only the cellRegion0 as rotating cellZone? You only need to add the ggi patches that are in the rotating cellZone. I do not know if that is the StatorGGI or the RotorGGI, it depends on how you named them.

Regards,
Tom