CFD Online Discussion Forums - BC's for k-omega SST (low / hi Re setups)

hi everyone,

i have been testing my k-omega SST setup for OF using a simple flat plate geometry, and BC's i have worked out from looking at a number of other posts on the issue. although there is a *lot* out there on the setups you need to use, i dont seem to get the impression that there has been widespread agreement on how the model is supposed to be implemented :D

anyway, so i have a low Re and a hi Re mesh. the BC's for the two meshes are:

For the hi Re mesh:

Code:

'k'

WALL

{

  type   kqRWallFunction;

  value  uniform 1;

}



'omega'

WALL

{

  type   omegaWallFunction;

  value  uniform 1;

}



'nut'

WALL

{

  type   nutkWallFunction;

  value   uniform 0;

}

and for the low Re mesh:

Code:

'k'

WALL

{

  type   fixedValue;

  value  uniform 1e-12;

}



'omega'

WALL

{

  type   omegaWallFunction;

  value  uniform 1e9;

}



'nut'

WALL

{

  type   nutUSpaldingWallFunction;

  value   uniform 0;

}

Also attached is a plot of the non-dimensional parameters for the wall, using the standard definitions (i.e. not Cmu etc!). As you can see, the low Re result looks ok, but the hi Re BL is too think.

Using yPlusRAS to check the meshes, i see that the first node points for each mesh are in the correct region, so i cant quite work out what the problem is. BC's perhaps??

anyway, i would appreciate any feedback on anything obvious i have gotten wrong + am quite keen to 'finalise' the 'proper' approach for the current implementation of k-omega SST (OF v2.1.1)

thanks a lot in advance!
Jonathan