[srsel6]

Hi everyone,

I'm trying to setup a dynamic mesh for a sinusoidally displaced piston. Seen in the attached pictures is my geometry. In Picture1.jpg and 2:

Green -- Defined piston face
1 -- "Reservoir" of fluid
2 -- Bridge connecting Reservoir and working chamber
3 -- working chamber
X -- point at which upon the piston reaches, Fluent crashes
4 -- Ignore this, just a bad mesh element I can't seem to get rid of.
Red arrows -- Fluid flow direction

I obtained picture 2 by drawing and meshing it directly, just to help illustrate my problem.


What I'm trying to do is to move the piston to the position as seen in Picture2.jpg where the fluid flow from the bridge to the working chamber is getting more and more cut off as the piston moves downward. However, when the piston reaches the "X" spot, Fluent gives this error and crashes:


Error at Node 0: coalesce_rib_faces: can't interpolate data, zones of different type detected.


I've tried looking around but no luck in finding the solution so far. I understand that making a complete cut off like that results in mesh topological change but I'm not sure how to configure it. Does anyone have any clue on how to solve this problem?


I've found this video on Youtube, which shows that it should be possible to have some sort of periodic mesh interface

https://www.youtube.com/watch?v=8cBA1fWP0QQ