Deforming mesh problem - Zones definition
 

Hi everyone,

referring to this youtube video https://www.youtube.com/watch?v=fbaV_knzzks
which is a part 1 tutorial for a dynamic mesh problem for a piston and reed valve, could you please explain the utility for the fluid_valve_prisms zone and the fluid_stationary_prisms zone ?

One more question, why defining the gravity force on the piston in UDF. Why not defining a global gravity force in operating conditions ?

Thank you in advance.