An open Brayton cycle engine operates with a compressor-pressure ratio of 6, an inlet temperature of 20 C and inlet pressure of 1 bar, and a turbine-inlet temperature of 950 C. The engine drives an electrical generator that produces 25 MWe with a generator efficiency of 90%. For the following systems find the thermal efficiency, the specific work[kJ/kg], and the air mass flow rate [kg/s], if the compressor and turbine efficiencies are 80%. Assume the air is an ideal gas with constant specific heats. Its specific heat ratio is 1.4 and gas constant is 0.287 kJ/kg-K. a) A regenerative Brayton cycle with a regenerator effectiveness of 80%. b) Cycle of part (a) with intercooling to 20 C.