[nathanricks]

Hello, I’m just wondering if someone is able to help me in regards to 3D dynamic mesh in Fluent 15.0, with the mesh created in ICEM CFD. The general geometry is of a throat/lung system, so not simple cylinders, etc.

I’ve written a UDF that moves the wall mesh in the desired motion (when tested using “Display Zone Motion” and “Preview Mesh Motion”), however I cannot get the boundary layer cells to move with the wall mesh. In the “Preview Mesh Motion”, the boundary layer cells are stationary, and new cells are created to fill the space between the boundary layer and dynamic wall. Most dynamic mesh examples I have found are in 2D, and do not include a boundary layer that is changing shape. You can see attached one cross section that shows the issue.

I found in the ANSYS manual “11.7.2 Specifying the Motion of Dynamic Zones”, where there is a section discussing “Specifying Boundary Layer Deformation Smoothing”. It states: “Note that the boundary layer has to be a separate fluid zone from the adjacent fluid zone.”

The unstructed mesh was created in ICEM by a previous member of our group that did not plan for dynamic motion, so the fluid zone is a single zone. Is there a way I can separate the boundary layer zone and inside fluid zone in ICEM or fluent without starting the mesh again (the mesh is relatively complex)? The boundary layer consists of prism cells, and the inside fluid zone of tetrahedral cells. I’ve tried to use this fact to create new parts in ICEM, but I am left with uncovered faces that I wasn’t able to repair.

Any insight in how to split the fluid zones, or how I can work with a single fluid zone, would be greatly appreciated!

Thanks in advance,
Kind Regards,

Nathan Ricks