Modelling the future of aviation

Abstract

The aviation sector accounted for 3.4 to 4.0% of the total anthropogenic radiative forcing in 2015. The sectors’growth is several percentage points larger than the annual fuel efficiency gain, resulting in an increasing climatechange impact. The world formulated goals for 2050 to limit anthropogenic climate change, the aviation sectorrequires a mix of fuel consumption reducing technology, increased operational efficiency and carbon offsettingto contribute to the goals.The Aviation Integrated Model (AIM) developed at the University of Cambridge resolves the impact of tech-nological and operational choices, but requires detailed knowledge of the technological development. This workis directed to retain the air traffic and fleet resolution model of AIM, while utilising a different performancemodel. Aircraft performance is modelled by technology trends to assess a range of technology options (such ashybrid electric flight or different aerodynamic configurations) at limited required knowledge while retaining themodel’s physical basis.The model uses the Breguet range equation and fuel fractions updated with Lissys’ Piano-X data to resolveaircraft fuel consumption with limited modelling error. The fuel and carbon dioxide emissions have an averagenormalised root-mean-square error of three percent compared to AIM, while nitrous oxide emissions incur a1.5% error.A case study to demonstrate the capability of the model has been performed to investigate the possibilities forhybrid electric flight serving a significant market share before 2050. The current trends in annual fuel efficiencyincrease and increase in battery specific energy do not result in a significant market share or reduction of aviationemissions for hybrid electric aircraft before 2050.To achieve a 10% decrease in carbon dioxide emissions, the annual increase of the aircraft fuel efficiency hasto be increased from 1.1% per year to 1.5% and the annual battery specific energy increase is required to goup to 5.67%. The required increase in both battery specific energy and the aircraft performance parameters issignificant, which makes a substantial reduction of emissions of the aviation sector by hybrid electric aircraftbefore 2050 improbable.