Impact of different fuel usages on thermodynamic performances of a high bypass turbofan engine used in commercial aircraft

Abstract

In this study, energy, exergy, and sustainability analyses are performed for the PW4056 engine to observe the different fuel effects on the thermodynamic performance of a turbofan engine. For this purpose, energy and exergy analyses are performed at the same dead state conditions, and then sustainability analyses are conducted for kerosene and hydrogen-powered engine and its main components. Also, nineteen thermodynamic performance metrics are adapted for the purpose of the study and used to compare the fuel performances. It is found that the fuel mass flow of the hydrogen fuel (1.03 kg/s) is lower than the kerosene fuel (2.85 kg/s), the exhaust gases mass flow of the hydrogen fuel (117.14 kg/s) is lower than the kerosene fuel (118.96 kg/s). The minimum exergy efficient component is determined as the combustion chamber in both cases, which are 64.24 % for kerosene case and 58.20 % for hydrogen case. The lowest relative exergy loss ratio is calculated to be 28.28 % for Fan outlet loss for hydrogen case, while the maximum relative exergy consumption ratio is calculated to be 51.93 % for combustion chamber for hydrogen case. The maximum productivity lack ratio is computed as 161.65 % for combustion chamber for hydrogen case, whereas the minimum relative fuel exergy waste ratio is computed as 0.02 % for high pressure turbine for hydrogen case, The highest exergetic improvement potential rate is obtained to be 24231.48 kW for combustion chamber for hydrogen case, while the lowest product ratio indicator is found to be 17.03 % for low pressure compressor for kerosene case. Furthermore, the minimum exergetic sustainability index is obtained to be 1.39 for the combustion chamber for the hydrogen case, whereas the maximum environmental effect factor is obtained to be 0.72 for combustion chamber for hydrogen case. On the other hand, with the usage of hydrogen fuel; it is observed that the exergy efficiency of the overall engine decreases from 26.9 % to 24.3 %, the ecological effect factor of the overall engine goes up from 3.712 to 4.113, the exergetic sustainability index of the overall engine rises from 0.321 to 0.369, and the waste exergy cost flow of the overall engine increases from 17.41 × 10 −3 US$/kW to 19.09 × 10 −3 US$/kW.