Integrated Performance Assessment and Decarbonising Potential for Aircraft Retrofitted With Sustainable Aviation Fuels

Abstract

Abstract The aviation industry is transitioning towards sustainable fuels from conventional fossil-based jet fuels to make air travel sustainable and environment-friendly. Hydrogen, Ammonia, and Methane are all potential long-term solutions since their implementation relies heavily on the redesign of existing aircraft configurations. Sustainable aviation fuels (SAF) on the other hand, due to their similar physico-chemical characteristics with conventional fossil-based jet fuels, are an effective drop-in solution for both short and long term. This solution enables next, current, and older generation aircraft to reduce their carbon footprint. This paper focuses on the retrofit application of SAF for an older-generation trainer jet aircraft for defence applications and aims to demonstrate the performance, economic and environmental impact of using the alternative fuels. A baseline high-manoeuvre mission profile with Jet A-1 is established, upon which all the SAF variants are compared. Reductions in fuel weight, in-flight CO2 as well as NOx emissions of up to 2–3% were observed, which are mostly attributed to the properties of the alternative fuels. Contrary to the fuel weight savings, higher operational costs are expected due to the higher SAF costs. At engine level, the fuel burn reduction enables a slight decrease in turbine entry temperatures. Finally, when switching to SAF, there exists shortcomings in terms of maximum operational range, mainly attributable to its lower density and consequently, lower energy stored in the fuel tanks.