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How to enforce zero velocity along walls of rotating channel?

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Old   June 19, 2020, 10:25
Default How to enforce zero velocity along walls of rotating channel?
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I am working on rotating turbulent channel flow and have test it for 2D & 3D. However, I keep getting non-zero velocity for the node point at the wall. This causes a sharp transition from wall surface to fluid flow which is unphysical. The solver works fine when I set rotation to zero and thus, I suspect I may have set my rotation incorrectly.

For my 3D solver, I set periodic boundary conditions along x and z directions. The flow is driven by dP/dx=-1 which is specify in the periodic conditions. To introduce rotation, I set the walls at y=-h & y=h to rotate along the z-axis at -20 rad/s.
I also try using frame motion instead but the result is much worst. I have no idea how to correctly introduce the rotation.

I can't upload the image here and thus, I have add the relevant link.

Without rotation, the velocity profile is alright as both of its ends starts from zero.
https://imgur.com/oyqMzOs

However, with rotation and at a nonzero distance from rotational axis, both ends of the velocity profile is equal to the wall rotational velocity at that point.
https://imgur.com/FdGa5fm

How do I ensure that both ends of the velocity profile starts from zero? According to the paper I am using, the "wall friction velocity is prescribed and kept constant in all numerical computations" and I believe that is the key to my problem. However, I can't seem to explicitly compute the wall friction velocity on Fluent...
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Old   June 19, 2020, 10:56
Default Wall Motion
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You have set walls to be moving, therefore, it is obvious that the velocities at the nodes on the walls are non-zero. If you don't want that, i.e., if the walls are stationary with respect to inertial frame, then you should set their absolute velocity to 0 or their relative velocity equal and opposite to that of cell zone velocity.
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Old   June 19, 2020, 11:54
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Thanks for the response! I resolved it by manually removing the velocity profile from the imposed wall rotation.
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Old   August 5, 2020, 04:45
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hello cfdnewb123,
Could you please explain in detail how did you solve the problem? I am facing a similar problem. Thank you so much.
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