i mean, i export an iges file, then i resurface it through pro surf, then i open it in pro-am, but how can i know if it's always in mm, or it has turned to meters ? i took a look in the utility panel, but nothing...

vdis vx vx

and pick 2 vertices.

Use the range command

cset news fluid

range cell cset

similarly for vertices,etc.

ok, both the procedures are right, i retrieve the extent of cell set, but what i meant what "i do set meters or millimeters before running the simulation under 'run analysis interactively' or i have to trust star-cd ?" thank you again

Once you know the units you pick the right one, you should see the scale factor used in the geom command that will show up in the output window/ in the history.

Star always wants its geometry in meters. The second parameter after geom in the geom command is the scale factor between model units and meters.