Advanced exergy analyses to evaluate the performance of a military aircraft turbojet engine (TJE) with afterburner system: Splitting exergy destruction into unavoidable/avoidable and endogenous/exogenous

A conventional and advanced exergy analysis of a military aircraft turbojet engine is presented in this paper. In this framework, the main exergy parameters of the engine components are introduced while the exergy destruction rates within the engine components are split into endogenous/exogenous and avoidable/unavoidable parts. Also, the mutual interdependencies among the components of the engine and realistic improvement potentials depending on operating conditions are acquired through the analysis. As a result of the study, the exergy efficiency values of the engine are determined to be 39.41% at military (MIL) mode (maximum engine thrust operation without afterburner fuel combustion) and 17.90% at afterburner (AB) mode (maximum engine thrust operation with afterburner fuel combustion), respectively. The system has low improvement potential because the unavoidable exergy destruction rate is 93% at MIL mode and 98% at AB mode. The relationships between the components seem to be weak since the endogenous exergy destruction is 83% at MIL mode and 94% at AB mode. Finally, it may be concluded that the low pressure compressor, the high pressure compressor, the combustion chamber and afterburner exhaust duct of the engine should be focused on according to the results obtained.