Methodology for Sizing and Performance Assessment of Hybrid Energy Aircraft

TLDR

NASA’s Strategic Research and Innovation Agenda demands dramatic efficiency gains, making hybrid‑energy and electric aircraft a promising but challenging area for conventional sizing and performance methods. The study proposes a sizing and performance methodology for hybrid‑energy aircraft and plans future clean‑sheet designs to evaluate their full potential. The methodology is demonstrated through a design study of a battery‑and‑fuel hybrid single‑aisle retrofit, analyzing new design variables affecting sizing and performance. Benchmarking against a conventional reference aircraft shows up to a 16% reduction in block fuel burn for a 900‑nm off‑design mission when using a fuel‑to‑electric energy mix.

Abstract

The Strategic Research and Innovation Agenda and NASA goals have set new challenges for the aeronautical community via declaration of dramatic efficiency improvements. Because further evolutionary improvements do not appear to be sufficient, envisioning disruptive technologies turn out to be essential to reach the set of future targets. The design of innovative integrated energy–power systems is certainly a major promising element as can be shown by the increasing interest toward hybrid energy and universally electric aircraft. The consideration of these new types of aircraft represents a new challenge for conventional aircraft sizing and performance methods. As an extension of the conventional methods used for fuel-energy aircraft, a sizing and performance methodology for hybrid-energy aircraft is proposed. A design study of a battery and fuel hybrid-energy single-aisle retrofit is conducted to demonstrate the methodology and to analyze the implications of the associated new design variables on the sizing and performance. The benchmark against a conventional reference aircraft shows a potential block fuel-burn reduction up to 16% for a 900 n mile off-design mission stage length (using a mix of fuel energy to electrical energy of ). Clean sheet designs will be part of future work to assess the full potential of hybrid-energy aircraft.