Wall edges should be already set as wall, then define the edges which are in your domain as interior.
Then set up wall edges and interior edges as rigid body

Getting error when doing it as five parts..

'Error: replace_c_in_f_layering: cell of wrong type or NULL cell detected at layering zone.
Error Object: ()'
@max, @Ghost

I can't attach the file here due to the 97kb file size limit..
I can mail them to you ides If I get the ids

don't have Fluent anymore, I am basing on my memory... ;)
If you are adding or deleting layers with your interior edges, take care to really set the right "side" of your edges. Thus interior means you have 2 adjacent cells.
If you are adding or deleting layers on the upper side, then you need to set height of cells for those adjacent cells in the meshing-options panel

That might be it. I had named all the interiors together. So now I might have to do it again right? Since each interior is in contact with different zone.


For 1,2,3 interiors I can put he adjacent cell size as 1 (sqr mesh of size 1 mm) What will I put for the other value? 0?

Should I put cell height for edges that are not in contact with deforming part?

No it is ok, if you regrouped all interior edges together.
Attachment 11033
Basically you need to set edge C as stationnary. Edges A,B,1,2 & 3 as rigid body.
That's it.
AS you can see edges 1,2 and 3 have 2 adjacent regions (yellow and white)
For edges 1,2 and 3 specify the cells height for the right adjacent cells. (you have to understand here if edge side belong to the yellow domain, or the white one).
If you specify 0, then you don't have add/suppress layering (this value should be set for the non-adjacent region)

Edge AB,1.2.3 are righd ok.

4,5,6 are also rigid bodies rite and the semicircle part of piston should be rigid body rite.

no edges 4,5 and 6 belong to another domain which has to be define as rigid body (I forgot sorry)
So in Gambit define the semi-disk as fluid domain (call it moving or whatever), and in Fluent define this region as rigid body.

So if we define a fluid region as rigid body then I don't need to define each edge individually... all of them will be treated so..

I think I grouped all of them as 1 single edge when meshing so I think I will go back and start from the mesh again. Will get back soon with new queries

Meshing finished
 

This basically finished the meshing part of the project. I will continue the topic as another thread on model selection.
The topic is continued here.