I´m quite new in Fluent. How can i do to modify my mesh in Gambit and come back in Fluent keeping up the boundary conditions, solver options, viscous options, operating conditions... Thanks a lot

I think that the best way is to save a file with your inputs (bc's, models, etc.), then modify your grid keeping the same names for your zones (inlets, outlets, etc.). After that open in FLUENT your old cas and dat files, and select the read cas menu command. There you must select the modified grid file. Afterwards you read the bc-file that you had saved.

Notice: In order to save a bc-file use the file/write-bc TEXT command (not menu command), and the file/read-bc to read respectively.

I think that the above will solve your problem.

Regards Ilias