There is currently no direct integration or import functionality available from Catia or other CAD software.
To import CAD models, you first have to export the geometry from your CAD software to STEP or IGES file format, and then import it into FEATool Multiphysics/CFDTool. If the geometry model is very complex with a lot of fine details it might also be necessary to first simplify it and/or perform clean up in your CAD software in order for it to easily mesh. Note that although faceted formats such as STL and OBJ also are available to import, these are non-exact approximate geometry formats, more prone to errors, and STEP/IGES formats should therefore primarily be used when available. See the documentations section on geometry import and export for more information: