An evaluation using various operating conditions such as the maximums of: power, power density, ECOP and ECOL optimization functions for the analysis of turbojet engines is reported. Although, these well-known optimization functions were applied for various cycle types by researchers, the application of these methods for aircraft turbojet engines have not been explored. To this effect, a Brayton cycle including diffuser and nozzle together with the compressor, combustion chamber and turbine with various irreversibilities was considered. Engine irreversibilities are taken into account through appropriate efficiencies for each component. Different parameters influencing the cycle performance are examined such as compressor pressure ratio, cycle temperature ratio, compressor and turbine efficiencies, altitude and flight Mach number. The cycle performance was assessed utilizing the maximum power (MP), power density (MPD), Ecological Coefficient of Performance (ECOP) and Ecological Function (ECOL) conditions. In addition, the size variation of individual engine components and their contribution to the overall performance was also assessed under maximum power, power density, ECOP and ECOL conditions. The comparisons show that the design parameters at the maximum ECOL and maximum ECOP conditions may lead to smaller, more efficient and lower fuel consumption for turbojet engines than those at maximum power and maximum power density. However, on a component basis (compressor, combustion chamber, turbine and nozzle) the engine power, thrust, thermal efficiency, size and TSFC can be enhanced when utilizing the MP, MPD, ECOP and ECOL optimization functions.

报告了使用各种运行条件（例如：功率、功率密度、ECOP 和 ECOL 优化函数的最大值）对涡轮喷气发动机进行分析的评估。尽管这些众所周知的优化函数已被研究人员应用于各种循环类型，但尚未探索将这些方法应用于飞机涡轮喷气发动机。为此，考虑了包括扩散器和喷嘴以及具有各种不可逆性的压缩机、燃烧室和涡轮机的布雷顿循环。通过每个组件的适当效率来考虑发动机的不可逆性。检查了影响循环性能的不同参数，例如压缩机压力比、循环温度比、压缩机和涡轮效率、高度和飞行马赫数。利用最大功率 (MP)、功率密度 (MPD)、生态性能系数 (ECOP) 和生态功能 (ECOL) 条件评估循环性能。此外，还在最大功率、功率密度、ECOP 和 ECOL 条件下评估了单个发动机部件的尺寸变化及其对整体性能的贡献。比较表明，与最大功率和最大功率密度下的设计参数相比，最大 ECOL 和最大 ECOP 条件下的设计参数可能会导致涡轮喷气发动机更小、更高效和更低的燃料消耗。然而，在组件基础上（压缩机、燃烧室、涡轮和喷嘴），当利用 MP、MPD、ECOP 和 ECOL 优化功能时，可以增强发动机功率、推力、热效率、尺寸和 TSFC。