Setting up a injection cylinder
 

Hello,

I try to set up a simulation for an injection of a fluent in a cavity. At the moment I try to set up the shrinking of the volume of the injection-cylinder during injection (to press -in an VOF Model- the fluid in the cavity). Probably this is quite simple, but I´m new to the program and it gives me quite a hard time.

My thought is to define the movement of the injection-piston as a moving wall at the headboard of the injection-cylinder.

Can this model work ?

If it works:
For shrinking the volume of the cylinder, do I need to write a UDF (I would take the macro "define_Geom" (?)) or is there an easier way, for example with profiles? I was thinking about the moving wall as a face moving in one direction, the mesh of the body adapting to the change. Is that possible ?

The geometry of the injection-cylinder is quite simple, only an cuboid with small radiuses over the length.

Would be great if someone could help me.