Answer Happy

a = A small-scale replica of a business jet Gulfstream G650 is tested within an aerodynamic wind tunnel. When set under its cruise flight settings, the aircraft model exhibits a lift coefficient Cl = 0.45 and a lift-to-drag ratio C[/CD = 17. In real life, the G650 aircraft has a lifting area of Aref = 120 m² and an operational mass (fuel & payload included) of m= 40 tons (1 ton = 109 kg). Consider that the aircraft is cruising at an altitude of 40,000 ft (where temperature is Talt 216 K) whereas facing a (uniform/constant) wind whose speed is 20 m/s. 1) Evaluate the atmospheric density and pressure at this altitude 2) Evaluate the speed and the corresponding Mach number that the actual aircraft must fly for its aerodynamic performances (i.e., lift coefficient and lift-to-drag ratio) match those of the wind tunnel test 3) Evaluate the propulsive power to be delivered by the engines for the aircraft overcomes the aerodynamic drag, under those conditions 4) Evaluate the stagnation (absolute) pressure measured by the aircraft's pitot probes, under those conditions