Exergy Analysis of a Turbojet Engine Modeled as a Lumped Parameter System

The application of exergy performance analysis to the transient operation of a singlespool turbojet engine is studied. This work determines under what conditions the steady exergy analysis methods can be successfully applied to the transient operation of a turbojet engine. The engine is modeled using cycle analysis with compressor and turbine maps for off-design component performance. The engine\u27s transients are modeled with the use of plenum volumes. By applying an exergy balance, with the inclusion of the critical wake analysis, to the system, the engine thrust is related directly to the rate of entropy generation in the system. Three types of transient events are studied and include: a) throttling, b) power extraction from the turbine and c) engine acceleration. The results show that for physically possible transient maneuvers, the engine thrust calculated using the steady exergy methods tracks the actual thrust during transients