Reference no: EM133207423

A 10-stages axial-flow compressor of 50% reaction design has a mean blade velocity of 250 m/s and the blade inlet angle for each row is 45°. The ratio of flow velocity to blade velocity is 0.75, the work done factor for each stage is 0.87 and the isentropic efficiency of the compressor is 0.85. The mixture gases of air and fuel then enter an axial-flow gas turbine at 11.5 bar, 950° and leave at 4 bar. There are 10 stages, each developing the same specific work with the same stage efficiency. Assuming each stage of turbine, the flow velocity is constant throughout at 160 m/s, the mean velocity is for the blade velocity of 200 m/s, and the polytropic efficiency is 0.85. Assuming an air inlet temperature for the compressor of 20° and Y = 1.4. For the gas velocity entering and leaving the turbine are approximately equal, Y = 1.333 and cp = 1.15 kJ/kg K for the gases, calculate,

a. The exit angle of the blade for the compressor,

b. The pressure ratio of the compressor,

c. The pressure ratio of the first stage for the compressor,

d. The blade angles at the mean for the stage turbine,

e. The overall isentropic efficiency of the turbine,

f. The stage efficiency of each turbine stage.