How to prepare imported files for Saturn ?

Hello everyone,

I will describe my problem by step !

The goal :
I want to use an imported piece and study the flow inside.

The pieces I used were modeled with Solid Edge and export in .step.

To illustrate my tests, i will take a tube as example.

First test:
- Importing.
- Meshing.
- Problem identified: The volume has been modeled in the thickness, between the inner and the outer surface.
- Processing with Saturn.

Displaying :
In Post-Pro we see that the fluid flows in the thickness of the part and not inside, because the logical volume has been modeled in this area.

Possible solutions :
1 - Following the import, in "Geometry", remove all external surfaces and keep only the interior surfaces to create the volume.
Solution discarded because the process is too long for a complex part.

2 - Make a Boolean operation, Create a cube and place the piece in the center, then "cut" the part, the mesh volume is expected to be create inside.
I am currently testing this solution, for now without success.

Questions :
Do you know a better way to achieve this goal ?

Thank you in advance