Learning Forum

[Kail Break]

How do you move an object in a circle during the simulation to model orbital shaking? Even a link to a video where someone moves soemthing in the simulation would help.

[Rob]

There are a couple of tricks using sliding mesh in Fluent. Please post a sketch of what's moving and the motion path. 

[Kail Break]

I am moving this hollow cylinder it has an 11.5mm outer radius. Its moves in a circle with a radius of 18mm at various RPM. The centerpoint of the hollow cylinder follows the motion path. 

[Kail Break]

I have the mesh set up and the model initialized. I just need to shake the model.

[Rob]

So, the outer casing is fixed and the core moves on an eliptical path? Or the whole lot moves? For the former you may need moving mesh, for the latter it's more a case of sliding mesh and reference frames. 

[Kail Break]

The whole lot moves. 

[Rob]

OK, what you need to do is cheat. We can mess with gravity, but that needs UDFs. If you can break the motion into circular sets what you can do is use sliding mesh and mess with the relative motion. You may need a "dummy" block of solid with a very coarse mesh to do this. Have a look for the vertical axis wind turbine (VAWT) threads as that's how we do those.