(a) What are the main components of afterburner; show the process of thrust augmentation on an...

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(a) What are the main components of afterburner; show the process of thrust augmentation on an enthalpy-entropy plot for a turbojet engine fitted with an afterburner. [25%] (b) An air breathing engine flies at Mach 2 at an altitude where the ambient temperature is -50°C and the ambient pressure is 10kPa. The specific heat ratio of air is 1.4 and the specific heat capacity of air is 1004J/kgK. The air flow rate of the engine is 25kg/s. The fuel flow rate is 3% of airflow rate and has a heating value of 42,800kJ/kg. Assuming that the exhaust jet velocity is 1050m/s and the nozzle is perfectly expanded; calculate the following performance parameters. (c) (i) (ii) The thrust specific fuel consumption (iii) The propulsive efficiency (without considering fuel injection) (iv) The overall efficiency of the engine The net (uninstalled) thrust of the engine A turbojet engine uses aviation kerosene as fuel, which has a calorific value of 43MJ//kg. The fuel consumption is 0.18kg per hour per N of thrust, when the thrust is 9kN. If the aircraft flies at a speed of 500m/s and the mass of air passing through the compressor is 27kg/s, calculate the following: (i) Mass of fuel consumed in (kg/s) (ii) The fuel-air ratio (iii) Thermal efficiency of the engine [15%] [5%] [10%] [15%] (iv) The overall efficiency of the engine. [5%] [5%] [10%] [10%] (a) What are the main components of afterburner; show the process of thrust augmentation on an enthalpy-entropy plot for a turbojet engine fitted with an afterburner. [25%] (b) An air breathing engine flies at Mach 2 at an altitude where the ambient temperature is -50°C and the ambient pressure is 10kPa. The specific heat ratio of air is 1.4 and the specific heat capacity of air is 1004J/kgK. The air flow rate of the engine is 25kg/s. The fuel flow rate is 3% of airflow rate and has a heating value of 42,800kJ/kg. Assuming that the exhaust jet velocity is 1050m/s and the nozzle is perfectly expanded; calculate the following performance parameters. (c) (i) (ii) The thrust specific fuel consumption (iii) The propulsive efficiency (without considering fuel injection) (iv) The overall efficiency of the engine The net (uninstalled) thrust of the engine A turbojet engine uses aviation kerosene as fuel, which has a calorific value of 43MJ//kg. The fuel consumption is 0.18kg per hour per N of thrust, when the thrust is 9kN. If the aircraft flies at a speed of 500m/s and the mass of air passing through the compressor is 27kg/s, calculate the following: (i) Mass of fuel consumed in (kg/s) (ii) The fuel-air ratio (iii) Thermal efficiency of the engine [15%] [5%] [10%] [15%] (iv) The overall efficiency of the engine. [5%] [5%] [10%] [10%]

Answer rating: 100% (QA)

a The main components of an afterburner in a turbojet engine include a fuel injector a flame holder and a nozzle The afterburner is typically located ... View the full answer