1. For ramjet, scramjet and turbojet engines, first expression for propulsive efficiency: Mp 2uT ma[(1 +f)u² − u²]|| If the nozzle is unchoked (pe= pa) and the fuel-to-air ratio (f) is negligible. Prove that: uT 2 uT + 1/me(ueu)² 1 + (ue/u) =

Question C . Options A. Subsonic Nozzle B. Expansion Tube C. Diffuser D. Supersonic Nozzle

4Air enters the compressor of a simple gas turbine at p1 = 14 lbf/in2, T1 = 520°R. The isentropic efficiencies of the compressor and turbine are 83 and 87%, respectively. The compressor pressure ratio is 12 and the temperature at the turbine inlet is 2500°R. The volumetric flow rate of the air entering the compressor is 9000 ft3/min. Use an air-standard analysis. a) Determine the net power developed, in Btu/h.   b) Determine the thermal efficiency of the cycle.   c) The temperatures at the compressor and turbine exits in °R.   d) The temperatures at the compressor and turbine enters in °R rmine the net power developed, in Btu/h .

A turboshaft engine comprising a gas generator and a free power turbine is selected to provide propulsive power for a helicopter. The helicopter is hovering in ISA conditions at an altitude of 4100 feet. The following data applies to this engine at this static max power operating point. Intake mass flow: 8.9 kg/s Compressor pressure ratio: 24.5 Compressor isentropic efficiency: 88% Mechanical efficiency: (HP & PT shaft) 99% Combustion chamber pressure loss Combustion chamber inlet pressure 4% Combustion efficiency 98.8% Combustion chamber exit temperature: 1585K Gas generator turbine isentropic efficiency:  92% Power turbine isentropic efficiency: 90%   The effects of the intake and exhaust ducts may be ignored. It may be assumed that for: Air: Cp = 1.005 kJ/kg • K, y = 1.4, R = 0.287 kJ/kg • K Combustion gases: Cp = 1.148kJ/kg • K, y = 1.333, R = 0.287 kJ/kg • K A 6% direct bleed of air from the exit of the compressor is…