[ssizz]

Dear All,
In CFX-Pre 11.0,Boundary Details,only the component of the specified wall velocity that is tangent to the wall is applied. Mesh motion should be used if the desired wall velocity is normal to the wall, or has a component normal to the wall. Then, how to use Mesh Motion to do this? I want to define the boundary(wall) velocity that is normal to the wall,with an expression(different location on the wall，different velocity).
PS: Mesh Displacement normal to the wall is some nanometers,and Boundary(wall) velocity is some centimeters per sec.

[ghorrocks]

If there is velocity normal to the wall then either you need to define a moving wall (then look at the moving mesh tutorial examples) or define a mass source/sink at the wall to blow or suck fluid. I can't think of any other approach which is physically meaningful.

[ssizz]

Originally Posted by ghorrocks

If there is velocity normal to the wall then either you need to define a moving wall (then look at the moving mesh tutorial examples) or define a mass source/sink at the wall to blow or suck fluid. I can't think of any other approach which is physically meaningful.

Thank you.
I need to define a moving wall. I can not use Specified Displacement nor Specified Location to define the velocity normal to the wall. And I didn't see any tutorial example that show how to define the mesh velocity.
Did I neglect some examples？

[ghorrocks]

The ball valve tutorial is the one you are looking for. There are a lot more examples in this area in V12 so time to consider upgrading I think.

[ssizz]

Originally Posted by ghorrocks

The ball valve tutorial is the one you are looking for. There are a lot more examples in this area in V12 so time to consider upgrading I think.

Oh， I see “ velBallOld = areaAve(Mesh Velocity v)@Ball”in the CCL file. I neglected this previously.Now，I get the way.
Thank you！
Thank you！
Thank you！