In the Brayton cycle, what is net work?

• A. Net work equals turbine output plus compressor input.
• B. Net work equals turbine output divided by compressor input.
• C. Net work equals turbine output minus compressor input.
• D. Net work equals exhaust temperature minus inlet temperature.

Answer: (C)

In the Brayton cycle, the turbine performs work by expanding the hot gas, while the compressor uses work to compress the intake air. Net work is the leftover shaft work after paying for the compressor’s energy input. It is defined as W_net = W_turbine − W_compressor, representing the useful power available to drive a load.

This is positive when the turbine’s output exceeds what the compressor consumes. For example, if the turbine delivers 120 kW and the compressor requires 40 kW, the net work is 80 kW. The other ways of combining these terms or using a temperature difference don’t represent the actual net shaft work in the cycle.