[The]

Hello, I'm new to cfd so please go light on me

I want to extrude my mesh (automated polygonal) on the outlet surface (pressure outlet). So far so good, I set up the surface extruder, then the volume extruder with the surface extruder as input part and assigned the new surfaces as regions. Now: the surface extruder automatically creates an interface but now I have two boundaries on the same place (outlet). When I try to simulate its only getting calculated for the old mesh, not the extended. What type of interface do I have to choose? What boundary condition do I have to use for my interface regions? All I want to do is to relocate my outlet surface 0.5m backwards.

[ping]

it is not that clear what has gone wrong but maybe you did not assign the new part created but the extrusion to a region - read the help at Pre-Processing > Meshing > The Meshing Workflow > Extruding Surfaces from a Parts-Based Volume Mesh.
if it is simply an interface issue then you need an inplace interface to allow flow thru and the outlet might need setting too. also check you have volume mesh in the extruded volume.

[Kushal Puri]

Originally Posted by The

Hello, I'm new to cfd so please go light on me

I want to extrude my mesh (automated polygonal) on the outlet surface (pressure outlet). So far so good, I set up the surface extruder, then the volume extruder with the surface extruder as input part and assigned the new surfaces as regions. Now: the surface extruder automatically creates an interface but now I have two boundaries on the same place (outlet). When I try to simulate its only getting calculated for the old mesh, not the extended. What type of interface do I have to choose? What boundary condition do I have to use for my interface regions? All I want to do is to relocate my outlet surface 0.5m backwards.

Just change that old outlet boundary to wall it will automatically make interface.

[The]

Hello, thanks a lot for the replies. I used the false interface definition. Dumb mistake