engines with piston bowls

Gareth

Hi there

I have managed (eventually) to produce a working 2D engine simulation (just as an excercise to figure out how to do the moving meshes and valve events).

I'm trying to add a bowl cutout to the piston, but am having layering remeshing problems at the moment. FLUENT doesn't seem to like having a meshed region (quad or tri) under the dynamic layering region.

I am still using the built in piston movement functions (**piston-full** & **piston-limit**)in FLUENT 6.1.

I defined the edge between the moving bowl grid and the layer zone as an "internal boundary" and defined its movement using the **piston-full** UDF. The flat part of the piston and the bowl spline edge are defined as a wall and also use the **piston-full** UDF. The movement of the edge between the remeshing and layered zones is defined using the **piston-limit** UDF as usual. Done this way the mesh preview crashes at the first layering event, and if I use a quad mesh for the bowl and no "internal boundary", the mesh in the bowl doesn't move and thus crashes into the moving edge above it!

Has anyone had experience in this area?

Gareth