CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)
-   CFX (https://www.cfd-online.com/Forums/cfx/)
-   -   Modeling internal flow with normal velocities on walls- permeable walls (https://www.cfd-online.com/Forums/cfx/134279-modeling-internal-flow-normal-velocities-walls-permeable-walls.html)

Modeling internal flow with normal velocities on walls- permeable walls

Hi everyone.

I'm trying to simulate blood flow in a vessel, where the boundary condition on wall for u is no slip, but for v is a constant definite value. In other words, wall is permeable in y direction. How can I apply this kind of boundary to my problem in CFX?

 ghorrocks April 27, 2014 18:27

I presume you mean u is in the tangential direction and v is in the normal direction.

The easiest way of doing this would seem to be a normal no-slip wall with a mass source/sink applied to the wall which gobbles up fluid at your prescribed rate.

But now the question is what is the relation between source/sink intensity and the normal velocity?
Question is posed regarding that the problem specifies the normal velocity on the wall, and nothing more.

 ghorrocks April 27, 2014 18:55

Make the magnitude of the mass sink a function of the wall shear stress. I would not make it a function of normal velocity as it will then be mesh dependent.