Ph.D. Proposal
Jeremy Decroix
(Faculty Advisor: Dimitri Mavris)
"A Conceptual Design and Sizing Methodology for Dual-Fuel-Powered Aircraft"
Thursday, October 30
11:30 a.m. - 12:30 p.m.
Weber SST II Bldg, CoVE
Abstract:
Aviation’s transition roadmap to net-zero emissions is challenged by the limited availability of sustainable aviation fuel (SAF) and hydrogen (H₂), which constrains the immediate deployment of fully sustainable propulsion systems. Dual-fuel engines capable of simultaneously burning hydrogen and kerosene offer a practical transition pathway by adapting to evolving fuel availability, emissions regulations, and infrastructure readiness. However, the conceptual design and sizing of such engines have so far been limited to inter-turbine burner configurations, preceding the recent development of simultaneous dual-fuel burners. The objective of this thesis is to develop a conceptual design, sizing, and power management methodology for a dual-fuel powered aircraft to assess the performance of a simultaneous dual-fuel hydrogen/kerosene turbofan engine. This endeavor is complex due to three main challenges: the lack of efficient combustion modeling capable of representing dual-fuel combustion thermodynamics at the conceptual level, the introduction of an additional energy fraction (EF) design-cycle variable that creates an underdetermined engine-level sizing problem, and the need for a novel mission analysis framework supporting mission-varying EF schedule analysis. These gaps currently limit the ability to systematically explore simultaneous dual-fuel powered aircraft configurations at the conceptual design stage.
The proposed methodology introduces EF as a variable for both on-design engine cycle and off-design mission power management. To address the first challenge, artificial neural network-based thermodynamic models are derived from chemical equilibrium simulations to enable fast and accurate simultaneous combustion analysis. To address the second challenge, EF is formulated as a coupling design-cycle parameter in a multi-design-point (MDP) engine model and is set at the aircraft mission level by minimizing energy consumption while enforcing a static-margin constraint. To address the third challenge, EF is extended as an additional power management variable within a trajectory optimization framework, enabling the determination of mission-varying EF schedules that further improve the energy efficiency.
The proposed methodology is demonstrated on a notional A320neo-class aircraft, modified into a dual-fuel-powered configuration. One major drawback of hydrogen combustion is the increased production of water vapor at high altitudes. To alleviate the potential impact of additional contrail formation, the EF schedule analysis framework is applied to integrate contrail-formation-zone avoidance as an additional operational constraint aimed at further reducing the climate impact of dual-fuel combustion. The potential benefits in terms of energy consumption, block fuel, and CO₂ emissions reductions are assessed and compared against single-fueled kerosene and hydrogen reference configurations. Expected contributions to the literature include: a computationally efficient framework for simultaneous dual-fuel engine analysis; an integrated engine and aircraft sizing methodology resolving the underdetermined dual-fuel sizing problem; and a mission-level EF schedule analysis framework that enables the environmentally conscious operation of future low-emission aircraft. These outcomes directly support ongoing efforts to develop dual-fuel propulsion systems by providing a computationally feasible methodology for consistent dual-fuel aircraft design, sizing and power management during the conceptual design phase.
Committee:
Dr. Dimitri Mavris (advisor), School of Aerospace Engineering
Prof. Kai James, School of Aerospace Engineering
Prof. Jechiel Jagoda, School of Aerospace Engineering
Dr. Jimmy Tai, School of Aerospace Engineering
Dr. Eric Hendricks, NASA Glenn Research Center