Conceptual design and energy management analysis of a turbofan-based hybrid-electric propulsion system

Hybrid-electric propulsion systems offer the potential to make aircraft more efficient by using electric energy to cover a share of the total energy demand. However, resolving questions related to aircraft hybridization, such as the potential emission benefits and the energy management throughout the mission, is vital. This highlights the importance of holistic evaluation methods. Hence, this paper introduces a method for the design and evaluation of hybrid-electric propulsion systems. The method enhances current sizing methods by modeling a hybrid-electric turbofan and estimating electrical losses for the electric power train to explore energy management strategies. The method is demonstrated using the short-medium range concept aircraft D239. Initial simulations indicate a total increase in block fuel mass of approximately 1.8 % with constant hybridization throughout the 800 nm reference mission. However, optimizing the energy management strategy reveals a slightly improved result of a 1.25 % increase in mission block fuel. Key factors contributing to this improvement include using hybrid-electric power exclusively during the climb phase, shorter mission ranges, and omitting battery charging during flight. The paper concludes that further technological developments help to reduce the block fuel demand. However, an overall increase in block fuel mass persists under realistic assumptions. This highlights the need for further studies hybrid architectures and methodical refinement.

DDC Class

629: Other Branches

Funding(s)

SMR aircraft architecture and technology integration project

Options

Conceptual design and energy management analysis of a turbofan-based hybrid-electric propulsion system