Muddy points Since n=1-=_looking at the P-V graph, does that mean the farther apart the T1,T2 isotherms are, the greater efficiency? And that if they were very close, it would be very nefficient?(MP 1A.1 In the Carnot cycle, why are we only dealing with volume changes and not pressure therms?(MP 1A.2) Is there a physical application for the carnot cycle? can we design a carnot engine for a propulsion device?(MP 1A.3 How do we know which cycles to use as models for real processes?(MP 1A. 4 1.A Brayton Cycles (or oule cycles): The power Cycle for a Gas Turbine et engine engine and the corresponding cycle are given in Figure A-g stant pressure legs. Sketches of an For a Brayton cycle there are two adiabatic legs and two cor Combustor Combustor citb Inlet Nozzle Turbine and nozzle P Compressor Turbine compressor a Heat rejectio Figure A-4: Sketch of the jet engine components and corresponding thermodynamic states Gas turbines are also used for power generation and for closed cycle operation(for example for space power generation). a depiction of the cycle in this case is shown in Figure A-51A-5 Muddy points Since η = −1 T T 1 2 ,looking at the P-V graph, does that mean the farther apart the T1, T2 isotherms are, the greater efficiency? And that if they were very close, it would be very inefficient? (MP 1A.1) In the Carnot cycle, why are we only dealing with volume changes and not pressure changes on the adiabats and isotherms? (MP 1A.2) Is there a physical application for the Carnot cycle? Can we design a Carnot engine for a propulsion device? (MP 1A.3) How do we know which cycles to use as models for real processes? (MP 1A.4) 1.A.3 Brayton Cycles (or Joule Cycles): The Power Cycle for a Gas Turbine Jet Engine For a Brayton cycle there are two adiabatic legs and two constant pressure legs. Sketches of an engine and the corresponding cycle are given in Figure A-4. Turbine and nozzle Heat rejection to atmosphere Inlet and compressor Combustor q2 PCompressor exit Patm q1 a d P V b c Combustor Compressor Turbine Inlet Nozzle Figure A-4: Sketch of the jet engine components and corresponding thermodynamic states Gas turbines are also used for power generation and for closed cycle operation (for example for space power generation). A depiction of the cycle in this case is shown in Figure A-5