Steam injection and recovery in a hydrogen-powered auxiliary propulsion and power unit

Journal Article (2026)
Author(s)

Martin Van Schie (Student TU Delft)

Arvind Gangoli Rao (TU Delft - Aerospace Engineering)

Feijia Yin (TU Delft - Aerospace Engineering)

Alexander Heidebrecht (TU Delft - Aerospace Engineering)

Research Group
Flight Performance and Propulsion
DOI related publication
https://doi.org/10.1017/aer.2026.10188 Final published version
More Info
expand_more
Publication Year
2026
Language
English
Research Group
Flight Performance and Propulsion
Journal title
Aeronautical Journal
Issue number
1350
Volume number
130
Pages (from-to)
2394-2412
Downloads counter
16
Reuse Rights

Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.

Abstract

Aviation has a significant contribution to climate change, which is poised to increase in the coming years due to increasing demand in air travel. The A321 APPU aircraft could offer a significant improvement as it offers a synergistic combination of two interesting technologies-a fuel-flexible hydrogen combustion system combined with boundary layer ingestion, by introducing a hydrogen-powered auxiliary power and propulsion unit (APPU). This turboshaft engine is located in the tail cone and powers a boundary layer ingestion propulsor, producing approximately 15% of the thrust. To improve the efficiency of the APPU, the feasibility of the steam ijection and recovery (SIR) cycle is evaluated. This semi-closed water cycle can reduce fuel consumption and NOx emissions. Both the baseline and the SIR APPU are modelled in pyCycle, an open-source gas turbine parametric analysis tool. The baseline APPU engine was found to have a thermal efficiency of 45% and a mass of around 500 kg. The SIR cycle can reduce fuel consumption by up to 7% and decrease NOx emissions by approximately 33%, with an increase in engine mass of approximately 15%.

Files

License info not available