Preliminary Design of Integrated Partial Turboelectric Aircraft Propulsion Systems

Abstract

This paper presents a novel tool for the modeling of partial turboelectric propulsion systems together with a corresponding case study for a commercial single-aisle aircraft. In order to reduce the environmental impact of air traffic, radically new aircraft and propulsion concepts with a high market penetration are needed. Partial turboelectric propulsion systems seem to offer a promising option to achieve this. For the development of these propulsion systems, a preliminary design tool with a homogeneous and sufficiently high fidelity, both for turbomachinery and electric components, is needed. To address this, the authors of this publication have developed a tool based on the GasTurb software. The models developed, in particular for the electric components which together form the electric powertrain, are described here. In the case study, which demonstrates the coupling of the developed tool with an aircraft design environment, a conventional turboprop baseline aircraft is compared to a derived aircraft which features a partial turboelectric propulsion system with wingtip propellers. The latter are intended to reduce the induced drag, enabling a reduction of the aircraft's total shaft power demand compared to the conventional baseline aircraft. The comparison between the partial turboelectric aircraft and the baseline aircraft indicates that fuel reduction increases with power split. However, primarily increasing electric powertrain masses and a stagnating drag reduction result in lower additional fuel reductions for higher power splits. Despite these conclusions, the predicted induced drag reductions need further refinement as they were found to be optimistic. In summary, this publication presents a methodology and a set of physics-based component models for the preliminary design of partial turboelectric propulsion systems, so that the electric components can be investigated and optimized at the same high level of detail as the gas turbine.

Functional Hazard Assessment of the Propulsion Control System Designed for a Small Hybrid Electric Aircraft

“…For example, as part of its Green Deal, the European Commission has formulated the goal of zero-emission aircraft being ready for the market by 2035 (European Commission, 2020). Across the globe, a broad range of research initiatives is being implemented which focus on electrified propulsion systems (Pohl et al, 2022;Hofmann et al, 2019;Hoelzen et al, 2018), fuel cell technology (Miazga et al, 2021;Scholz et al, 2022) and sustainable aviation fuels (Abrantes et al, 2021;Holladay et al, 2020). One such upcoming trend and transfer technology into full electrical propulsion systems will be hybridization until sufficiently high energy densities are achieved for battery cells, as shown by Pornet et al (2015).…”