# Wall function for rotating or counter rotating wall

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 May 4, 2017, 17:29 Wall function for rotating or counter rotating wall #1 New Member   Join Date: Feb 2016 Posts: 10 Rep Power: 9 Hello, I am looking for formulation of standard wall functions for rotating or counter rotating walls. Since we are skipping the wall, the rotational speed of the wall cannot be modeled directly, instead it has to be modeled through extra terms in the law of the wall expression. Does anybody know how can I found the rotating version of wall functions? I searched through literature but most of the rotating walls use a rotating frame and since they are not modeling a counter rotating wall, there is no need to impose the rotation in wall functions explicitly. I found this paper by Rhode et al. but they do not explain how they come up with their formula: http://tribology.asmedigitalcollecti...icleid=1460204 Does anybody know a better reference with more detailed explanation? Thanks

May 5, 2017, 07:20
#2
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Paolo Lampitella
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Quote:
 Originally Posted by ferferimori Hello, Since we are skipping the wall, the rotational speed of the wall cannot be modeled directly, instead it has to be modeled through extra terms in the law of the wall expression.
What do you mean? For a given cell center next to the wall, the normal-to-the-wall line passing trough this point is usually well defined and intersects the wall at a unique point. As you know the wall velocity at that point, you can always formulate the wall function problem in a reference frame moving at the velocity of that point. Why not?

 May 9, 2017, 16:34 #3 New Member   Join Date: Feb 2016 Posts: 10 Rep Power: 9 Thanks Paolo, You are right. One should extract all the velocities in the relative frame and use them for the wall function/wall shear expression. For other people who are looking for the same procedure they can refer to a dissertation at TAMU by Demko (Prediction of flow in labyrinth seals). I found his discussion adequate and helpful. sbaffini likes this.

 Tags counter rotating wall, wall function