[mihaipruna]

I tried this, but, after meshing, looking in the boundary file it generated, all the STL patches are walls!
SHM:

sduct.stl
{
type triSurfaceMesh;
name sduct;
regions
{
Sductface1
{
name Sductface1;
type wall;
}
Sductface2
{
name Sductface2;
type wall;
}
SDuctInlet
{
name SDuctInlet;
type patch;
}
SDuctOutlet
{
name SDuctOutlet;
type patch;
}
}
}



Boundaries:

Sductface1
{
type wall;
nFaces 139535;
startFace 2352772;
}
Sductface2
{
type wall;
nFaces 13938;
startFace 2492307;
}
SDuctInlet
{
type wall;
nFaces 13938;
startFace 2506245;
}
SDuctOutlet
{
type wall;
nFaces 136863;
startFace 2520183;
}
)

[mihaipruna]

assuming my time 0 BCs are defined properly, does this even matter for simpleFoam to define the inlet as an inlet and the outlet as an outrlet,etc?

[kid]

Yes it does.

But you can overcome this "wall" by editing 0/u p adn all ... for -type "wall" to the one you want them to be like patch,empty,fixedValue; etc.
Also you will be required to edit /constant/polyMesh/ boundary file for same i.e for stl walls where ever you need different type , name it accordingly. Remember few will still be type wall.

Also point to be noted here is , this editing has to be done after meshing.

Note: It is just nature of problem one is solving. In your case some internal flow might be taking place . Generally for outer flow less or no editing is required. ( only my guess)

[mihaipruna]

hmm so far from the tests I did it seems inlets and outlets are overridden by setting the BCs.