a variable flow (in speed and direction) as inlet velocity
 

I want to simulate the flow over a rotating blade excluding the effects of the rotation (I know it sounds strange).
To do that I would need as inlet boundary condition a speed profile of increasing magnitude and direction.

Do you know if this is possible in Fluent?

Sounds like you need to use a boundary profile - essentially a text file containing a description of how your inlet boundary variables vary with distance along the boundary. See the user guide section 7.26 "Boundary Profiles" for more info.