[cmharwood]

Hello all,

I'm quite the CFD amateur, so please bear with me if I make any ignorant remarks.

I've been working on modeling flow past a foil in a rectangular flow channel. My focus is on the characteristic flow through a finitely-small gap between the foil tip and the wall. I'm paying special attention to the boundary-layer and vortex interactions, so my mesh is extremely fine near the foil tip and in the wake. I'm working with several meshes between 6 million and 16 million elements.

I've divided the flow domain into three segments. I've specified free-slip walls upstream of the first division, and no-slip everywhere downstream. By parameterizing the upstream division, I'm hoping to exert control over the boundary layer thickness on the wall. The third segment maintains the no-slip condition but does away with the structured mesh to spare me some elements, and because the vortices of interest convect out of the boundary layer pretty quickly.

I've formed the three sections into a multibody part in DesignModeler, and I've ensured that the mesh is contiguous. CFX Pre recognizes the setup as a single domain and automatically recognizes 1:1 contact regions. I've specified them as fluid-fluid interfaces with conservative flux in Pre.

When I execute the runs, however, I'm still getting a spurious wall (I think.) For whatever reason, it's walling-up my outlet and exiting with an overflow error. I've tried different ways of specifying the interfaces (manually and with automatic detection,) and I keep getting the same result for all of my meshes.

Is there some trick I'm missing? I haven't tried inserting a connection prior to meshing yet, but I was under the impression that its not necessary if the bodies form a single part with a contiguous mesh.

Thanks much,
Casey

[cmharwood]

Here's a figure of my domain and boundary conditions for reference.