Exergy-based Sustainability Analysis of a Low-bypass Turbofan Engine: A Case Study for JT8D

The growth in demand for air transport is a problem for the global and local environment. There are, moreover, fundamental conflicts with sustainable development objectives. Sustainability demands a sustainable supply of energy without causing negative environmental impacts of aircrafts and its engines. In this paper, an investigation of exergo-sustainability indicators is reported for a low bypass (0.96 to 1) turbofan engine with 72 kN thrust force. Six selected exergetic indicators are selected for the analysis. The study is based on three approaches: energy, exergy and sustainability. In this regard, considering thermodynamics laws and Brayton cycle equations, the exergy efficiency of the engine is 11% having waste exergy ratio of 0.348. In addition, exergetic sustainability index of the low bypass turbofan engine is found to be 0.316, while environmental effect factor is calculated to be 3.163. On the other hand, the recoverable exergy amount of the engine is zero since the emissions released from fan bypass duct and core engine exhaust cannot be recoverable in the engine.