[atul1018]

Hello All,


I am trying to simulated particle-laden backward facing step (BFS) case using DPMFoam. I am using mapped BC to provide fully developed turbulent flow at inlet (with centreline velocity as 10.5 m/s and average velocity as 9.39 m/s. To map the flow field, I am taking offset of 0.067m from inlet but unfortunately I am not getting fully developed flow at inlet with centre-line velocity as 10.5 m/s and average of 9.39 m/s. The peaks of mapped velocity at inlet is is 11.13 m/s *more than 10.5 m/s) and also the mapped velocity field does not satisfy no-slip condition (velocity at the wall are not zero). the the settings for mapped BC are as follows:


In blockMeshDict:

    inlet
    {
        type            mappedPatch;
        sampleMode      nearestCell;
        sampleRegion    region0;
        samplePatch     none;
        offsetMode      uniform;
        offset          (0.067 0 0);


       /* type    patch; */
        faces
        (
            (4 7 3 0)
        );
    }

In U.air

 

inlet
    {
        type                mapped;
        value               uniform (10.5 0 0);
        interpolationScheme cell;
        setAverage          true;
        average             (9.39 0 0);
    }

In omega.air

inlet
    {
      /*  type                zeroGradient; */
          type                mapped;
          value               uniform 129.448;
          interpolationScheme cell;
          setAverage          true;
          average             129.448;
    }

In k.air

inlet
    {
       /* type            zeroGradient; */

        type                mapped;
        value               uniform 0.331;
        interpolationScheme cell;
        setAverage          true;;
        average             0.331;
   }

I am also not sure about the meaning of certain keywords(value, average) used in mapped BC. I am hoping to get some idea about mapped BC to provide fully developed turbulent flow at inlet.


Best Regards
Atul