Ph.D. Defense

 Johannes Verberne

(Advisor: Dr. Dimitri Mavris)

A Design Methodology for Electric Aircraft Design Space Exploration with Higher-Fidelity Battery Degradation Modeling

Tuesday, August 11
2:00 pm EST
Collaborative Visualization Environment (CoVE) (Weber Building)

Abstract: The paradigm shift towards electrified aircraft introduces new aircraft-level behaviors resulting from the unique characteristics of electric powertrains. Unlike traditional fossil-fuel powertrains, electric powertrains are much more sensitive to degradation effects which introduces new design and operational challenges. This is particularly true for battery-electric powertrains which are constrained by fixed weight and tightly coupled power-energy dynamics. Consequently, battery degradation over time and through utilization cycles progressively reduces the overall aircraft performance and remaining capabilities.

A literature review shows that cycle-life effects and operational considerations are only occasionally integrated comprehensively into early-stage aircraft design, especially within the context of Advanced Air Mobility (AAM). State-of-the-art methods are susceptible to producing overly conservative aircraft designs, which may result in reduced aircraft performance and utility. This dissertation aims to address this research gap by formulating and implementing a methodology to account for deficiencies in degradation modeling in early AAM aircraft design. Incorporating degradation feedback into the design loop and quantifying associated uncertainties can significantly enhance performance robustness, cycle life and the marketability of AAM aircraft.

Four research areas are identified. The first research area focuses on finding a suitable method to influence the electric battery degradation characteristics at the powertrain system level and assesses the importance of incorporating these effects. The second research area evaluates how the introduction of higher-fidelity battery degradation considerations alters the aircraft-level design space. The third research area evaluates whether incorporating degradation and cycle-life effects into AAM design space exploration leads to improved design solutions. Finally, the fourth research area investigates whether changing aircraft operations alone is sufficient to minimize the effects of battery degradation as compared to including these effects in early design.

The results show that aircraft sized through the developed design methodology in a use case representing a notional Pipistrel Velis Electro possess improved cycle-life performance as compared to aircraft sized using traditional considerations for battery degradation in early design.

Committee:
Dr. Dimitri Mavris (advisor), School of Aerospace Engineering
Dr. Brian German, School of Aerospace Engineering
Dr. Daniel Schrage, School of Aerospace Engineering
Dr. Cedric Justin, School of Aerospace Engineering
Dr. Simon Briceno, Jaunt Air Mobility