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Problems and A.B., Intelligent Microsystem Laboratory YunusBiomimetics AC, Michael Thermodynamics an engineering approach, McGrawHill, 2013 Problems 9-88 Air is used as the working fluid in a simple ideal Brayton cycle that has pressure ratio of 12, a compressor inlet temperature of 300K, and the turbine inlet temperature of 1000K Determine the required mass flow rate of air for a net power output of 70MW Assume constant specific heats at room temperature 9-91 An aircraft engine operates on a simple ideal Brayton cycle with a pressure ratio of 10 Heat is added to the cycle at a rate of 500kW; air passes through the engine at the rate of 1kg/s; and the air at the beginning of the compression is at 70kPa and 0C Determine the power produced by this engine and its thermal efficiency Use constant specific heats at room temperature 9-127C What is propulsive power? How is it related to thrust? 9-128C What is propulsive efficiency? How is it determined? and A.B., Intelligent Microsystem Laboratory YunusBiomimetics AC, Michael Thermodynamics an engineering approach, McGrawHill, 2013 Problems 9-130 A turboprop-aircraft propulsion engine operates where the air is at 55kPa and 23 on an aircraft flying at a speed of 180 m/s The Brayton cycle pressure ratio is 10 and the air temperature at the turbine inlet is 505 C The propeller diameter is m and the mass flow rate through the propeller is 20 times that through the compressor Determine the thrust force generated by this propulsion system Assume ideal operation for all components and constant specific heat at room temperature 9-131 How much change would result in the thrust of Prob 9-30 if the ropeller diameter were reduced to 2.4 m while maintaining the same mass flow rate through the compressor Note: The mass flow rate ratio will no longer be 20 9-132 A turbofan engine operating on an aircraft flying at 200 m/s at an altitude where the air is at 50 kPa and -20 C is to produce 50,000N of thrust The inlet diameter of the engine is 2.5 m; the compressor pressure ratio is 12; and the mass flow rate ratio is Determine the air temperature at the fan outlet needed to produce this thrust Assume ideal operation for all components and constant specific heats at room temperature and A.B., Intelligent Microsystem Laboratory YunusBiomimetics AC, Michael Thermodynamics an engineering approach, McGrawHill, 2013 Problems 9-133 A pure jet engine propels an aircraft at 240 m/s through air at 45 kPa and 13 C The inlet diameter of this engine is 1.6 m, the compressure ratio is 13, and the temperature at the turbine inlet is 557 C Determine the velocity at the exit of this nozzle and the thrust produced Assume ideal operation for all components and constant specific heats at room temperature 9-134 A turbojet aircraft is flying with velocity of 320 m/s at an altitude of 9150 m, where the ambient conditions are 32 kPa and -32 C The pressure ratio across the compressor is 12, and the temperature at the turbine inlet is 1400K Air enters the compressor at a rate of 60 kg/s, and the jet fuel has a heating value of 42,700kJ/kg Assuming ideal operation for all components and constant specific heats for air at room temperature, determine (a) the velocity of the exhaust gases, (b) the propulsive power developed, and © the rate of fuel consumption and A.B., Intelligent Microsystem Laboratory YunusBiomimetics AC, Michael Thermodynamics an engineering approach, McGrawHill, 2013 Problems 9-135 Repeat Prob 9-34 using a compressor efficiency of 80% and a turbine of 85% 9-136 Consider an aircraft powered by a turbojet engine that has a pressure ratio of The aircraft is stationary on the ground, held in position by it brakes The ambient air is at C and 95 kPa and enters the engine at a rate of 20 kg/s The jet fuel has a heating value of 42,700kJ/kg and it is burned completely at a rate of 0.5 kg/s Neglecting the effect of diffuser and disregarding the slight increase in the mass at the engine exit as well as the inefficiencies of the engine components, determine the force that must be appliied on the brakes to hold the plane stationary and A.B., Intelligent Microsystem Laboratory YunusBiomimetics AC, Michael Thermodynamics an engineering approach, McGrawHill, 2013 and A.B., Intelligent Microsystem Laboratory YunusBiomimetics AC, Michael Thermodynamics an engineering approach, McGrawHill, 2013 and A.B., Intelligent Microsystem Laboratory YunusBiomimetics AC, Michael Thermodynamics an engineering approach, McGrawHill, 2013 and A.B., Intelligent Microsystem Laboratory YunusBiomimetics AC, Michael Thermodynamics an engineering approach, McGrawHill, 2013