Stirling motor CFD simulation
I am trying to study the behaviour of the air inside a stirling engine but I'm having some struggles with fluent. I have already checked some discussions in this forum that helped me but I still have some questions.
This stirling motor has two pistons, these two pistons have a swinging movement, when one piston is moving to top dead center, the other is moving to bottom dead center and are both connected with a pipe. So I know that I have to use UDF for simulating the movement and also moving mesh, the question here is: I have to use two different UDF files?, one for each piston? Is it possible to use just one UDF file that could coordinate the pistons' movement? Also, it is a 3D simulation, will the UDF file work for all the faces of the piston inside the cylinder?
Also, the pistons and the pipe are three diferent files that I desgined and later put it together in assembly, so how should I put the boundary conditions at the extremes of the pipe and the inlet/oulet of the pistons? Because it is a compact motor, there aren't any inlet or outlet with the exterior, it is always the same air moving inside.
I insert some images so you can see the geometry.
Please could you give me any advide or some help?
Thanks for your attention.