Reply To: Piston motion problem: Dynamic mesh and fluid zone motion

[Federico]

Hello Lee, 

if all of your moving zones have the same motion, you can assign the same UDF Motion to each of them. In the Dynamic Mesh Zones settings, you will have the option to define individual center of gravity for each zone to differentiate them (although if you're after Rigid Body motion, it won't make any difference).

If you wanted to have different CG_Motion for each zone, you could create different functions for each of them and give each function a different name (1st argument to DEFINE_CG_MOTION).

I hope this helps. Let me know if you have other questions