Abstract
This paper presents effect of reference altitudes on the exergetic efficiency of a engine with the aid of specific exergy method. between 4000-9000 m. In the analysis, and exergy efficiency of the engine is found to be from 50.34% at 4000 m to 48.91% at 9000 m. Results of this study show that increase in reference altitude decreases the exergy efficiency and increases the energy efficiency of the engine. Additionally, specific exergy analysis can also be used as an integrated indicator for determining the exergetic efficiency.