Thank you very much to all
Unfortunately i had to use Ansys for the analysis.
I am currently modifying an existing Tank so that it has 03 compartments.
Also use PTC CREO SIMULATE but there are singularities that I could not eliminate in the end.
Personally really like PTC CREO.
Maybe i'm lacking in practice in the mesh methods that PTC / CREO uses, Thank you very much for your help.