From Gas Tables, by the Principles of Gas Dynamics, one can estiate the properties of fluid at outlet condtions by knoiwng Mach Number and altitude.
By using Software, one has to give staic pressure, Mach number,static temperature, speciic heat, gas constant, adiabatic index at inlet condtions, so all the required paramters like Mach number, static pressure, stangation pressure, static temperture, stagntion tempertue, velocity of fluid at outlet can be determined.
in Fluent you can use FarField boundary condition, where you can enter Mach number , pressure at 41K ft and corresponding atmospheric temperature . you need to keep the comutational boundary far from the aircraft ( 20 times aircraft length in all direction is good practice). Make sure you are using compressible flow and have set operating pressure to zero if you are entering the absolute pressure value in the b.c. panel. Use density based solver for this flow problem with implicit solution method