Answer Happy

This is related to propulsion
A turbofan engine with separate exhaust streams flying at a speed of 1100 km/hr at an altitude where the ambient pressure is 20 kPa. The total temperature of the gas at the inlet and exit of combustion chamber is 450 K and 1200 K, respectively. The total mass flow rate is 120 kg/s and mass flow rates in the engine core (mc) is 85 kg/s. The heating value of fuel is QR ~ 42000 kJ/kg. Exhaust speeds for the core and bypass streams are, respectively, 2000 and 1460 km/h. (i) Calculate the fuel flow rate, assuming the specific heat at constant pressure (cp) is 1.01 and 1.05 kJ/kg.K at the entrance and exit of the burner, respectively. (ii) Compute the net engine thrust considering both nozzles are perfectly expanded. (iii) If the pressure at exit of core nozzle is half of the ambient pressure, compute the net thrust produced from the core of the engine with exit nozzle area of 0.05 m². mb Bypass nozzle Bypass air Core nozzle m₂ = 120 kg/s mc = = 85 kg/s mf