A cold-air standard open Brayton cycle operates with a compressor pressure ratio of 12. Air enters the compressor at 14.7 psi. The minimum and maximum temperatures are 525 °R and 2600 °R, respectively. The isentropic efficiencies of the compressor and turbine are 82% and 85% respectively. The net power developed is 5.25 x 106
BTU/h. Evaluate specific heats at ambient temperature of 525 °R. Hint! You do not necessarily need to solve parts b-e in order!
a. Draw the process on a T-s diagram.
b. What is the mass flow rate of the air entering the compressor in lbm/hr?
c. What is the volumetric flow rate of the air entering the compressor in ft3/min?
d. What are the temperatures at the compressor and turbine exits in °R? Ans. 1189°R,
e. What is the thermal efficiency of the cycle? Ans. 32.68%