Correct way to export duct or pipe
 

Hi,


I have a quite simple question I guess :-)


I want to export and simulate a inlet duct for an airbox. I know that I need an inlet and outlet patch in the simulation later on, but I am not sure what kind of surface or body that they need to be?


My duct is just a simple body with 1 mm wall thickness that I can export from Fusion 360.

Do the inlet and outlet just need to be a patch/surface without any thickness?

And do I have to export all parts one by one or as one stl/obj file combining everything.


Thanks,
Marius

Hello Marius,

You only need to have the surface corresponding to the fluid volume you want to simulate, so if you only intend to simulation the flow inside the duct you need the inner surface of the duct (no need for thickness) + inlet + outlet.

About the STL/OBJ export: STL/OBJ format can handle surface naming, so does snappyHexMesh. But not all CAD software support this feature.

If Fusion 360 supports it, you can have one single STL/OBJ (pay attention to what settings/options are available when doing the export)
If it does not support it, you will need separate STL/OBJ files for inlet, outlet and wall.

Regards,
Yann