Tool objects could not be combined?

I’m trying to see how air flows through this air duct. I’ve simplified the model as much as possible, there’s a duct, a cone that it points at, and a box that it’s in. I don’t see how it can be made simpler. Anyone have any ideas what I could change to make it calculate the inner region?

Thank you

@core_support & @cfd_squad - do you mind guiding our user here?

@phazei, most likely the double layered structure of your model causes some trouble here. I would personally always avoid that (if it is somehow needed for whatever reason you can work around that).

Best,

Jousef

Double layered structure? I don’t follow, it’s modeled as a normal parametric object in Fusion 360. It’s essentially just a tube with a Y split in it.

I ended up manually connecting the containing box with the fan shroud in my modeler, then imported it and it seemed to work. Took ages to generate the mesh though.