Design Exploration of a Distributed Electric Propulsion Aircraft Using Explainable Surrogate Models

Abstract

Distributed electric propulsion in aircraft design is a concept that involves placing multiple electric motors across the aircraft’s airframe. Such a system has the potential to contribute to sustainable aviation by significantly reducing greenhouse gas emissions, minimizing noise pollution, improving fuel efficiency, and encouraging the use of cleaner energy sources. This paper investigates the impact and relationship of turbo-electric propulsion component characteristics with three performance quantities of interest: lift-to-drag ratio, operating empty weight, and fuel burn. Using the small- and medium-range “DRAGON” aircraft concept, we performed design exploration enabled through the explainable surrogate model strategy. This work uses Shapley additive explanations to illuminate the dependencies of these critical performance metrics on specific turbo-electric propulsion component characteristics, offering valuable insights to inform future advancements in electric propulsion technology. Through global sensitivity analysis, the study reveals a significant impact of electrical power unit (EPU) power density on lift-to-drag ratio, alongside notable roles played by EPU-specific power and applied voltage. For operating empty weight, EPU-specific power and voltage are highlighted as critical factors, while turboshaft power-specific fuel consumption notably influences fuel burn. The analysis concludes by exploring the implications of the insights for the future development of turbo-electric propulsion technology.