# Does real gas's entropy increase in $T$-$S$ diagram of Brayton Cycle efficiency?

I got T-S diagram for efficiency of Brayton Cycle, which includes ideal cycle (black line), real cycle (red line) and GE's cycle (blue line), can't understand the entropy, whether it increases or decreases, I draw a diagram of it and as u can see the entropy of GE's cycle goes between ideal cycle and real cycle, is it right or no? Got presentation this week and sure that professor will ask more detailed explanation for this diagram. If someone knows please explain.

• What's GE's cycle mean? – Chet Miller Nov 27 '18 at 14:16
• GE Power - company's name which has the gas turbine with highest efficiency. – Jakha Rakhmatzoda Nov 28 '18 at 11:17
• The T-s diagram shows entropy is added in cycle segment 2-3 (combustion, which occurs between engine stations 3 and 4, beware of possible confusion) due to breaking fuel molecules, this is the expected result. The increases shown in segment 1-2 (compression of air by ram, fan and compressor between stations 0 and 3) and segment 3-4 (expansion of gas, energy extraction by the turbine between stations 4 and 5) are due to compressor and turbine inefficiencies, these processes should be isentropic. See Polytropic Efficiency. – mins Jan 23 at 13:17