Repeat Prob. 9-109 using constant specific heats at room temperature. Prob. 9-109 Air enters the compressor of

Question:

Repeat Prob. 9-109 using constant specific heats at room temperature.
Prob. 9-109
Air enters the compressor of a regenerative gas-turbine engine at 310 K and 100 kPa, where it is compressed to 900 kPa and 650 K. The regenerator has an effectiveness of 80 percent, and the air enters the turbine at 1400 K. For a turbine efficiency of 90 percent, determine
(a) The amount of heat transfer in the regenerator and
(b) The thermal efficiency. Assume variable specific heats for air.