Thank you for your answer, I will try this way. Yesterday finally, I was able to import the solid body into the mesh section but now i have another problem. The solid body is made up of so many facets so i'm not able to do the name selection of the inlet and the outlet section. I read in other post in this forum that i have to do a Skin surface and i did it but then when I imported it in to the mesh section the surface created didn't appear. I also tried to do a wrap but i when i do it i return in the situation of many facets. Do you know if there is a way to glue the new surface on the solid body? or what i have to do to see the surface in the mesh or also in the set up to be able to set the boundary conditions? Thank you for your timen