One Year of Advancing Hydrogen-Electric Propulsion
The exFan project has successfully completed its first year, taking key steps toward hydrogen-electric propulsion for aviation. This EU-funded initiative brings together 10 leading European partners to develop cleaner, more efficient propulsion technologies.
Key Developments & Achievements
WP3: Balancing Performance and Efficiency
- Aircraft performance is highly influenced by ambient temperature.
- TU Wien has developed an aircraft model which includes contributions from all partners.
- Key operating points that are analyzed under ISA conditions: take-off and cruise
- Challenges that must be considered are hot-day take-off due to the occurring PEM fuel cell heat and the resulting size of the heat exchanger requirements
- Hybridizing the system with batteries can reduce heat exchanger size and pressure losses in the exFan propulsor but increases aircraft weight.
WP4: Understanding System Interactions
- Sensitivity analysis conducted to evaluate component interactions and their impact on mass and power demand.
- Models developed for key system components, including thermal management, gearbox, electric motor, and heat propulsor.
- Initial propulsion system design completed.
- Life Cycle Assessment (LCA) preliminary data gathered to assess environmental performance.
- Heat exchanger integration within the ducted fan improved performance but added weight.
- Two-phase cooling systems show potential for better heat transfer and lower system mass.
WP6: Enhancing Heat Exchange Efficiency
- Chemical surface treatments are targeted for improving heat exchanger performance by CIDETEC.
- Surface roughness of AlSi10Mg alloy produced by L-PBF technology modulated by chemical polishing process
- Electroless nickel (Ni-P) coatings developed on AlSi10Mg alloys with good adherence and improved corrosion protection
- Chemical treatments homogenously applied on complex TPSM structures
Sharing Knowledge & Building Networks
AIAA SciTech 2025: TU Wien presented exFan project research at this key aerospace conference and encouraged collaboration and knowledge exchange within the aviation and engineering communities.
Vienna Aviation Days 2025 – Join the Discussion
The Vienna Aviation Days return on 07-08 July 2025 in Vienna, Austria, bringing together experts from research, industry, and policy to explore the future of aircraft propulsion. The event will feature discussions on emerging technologies, challenges in scaling up innovations, and opportunities for collaboration.
Organized by the exFan Project and powered by Advanced Drivetrain Technologies GmbH, this event is open to all.
Stay tuned for updates and be part of the conversation!
Follow our progress
The exFan project is advancing hydrogen-electric propulsion with a focus on practical industrial applications. Stay informed on our developments and key milestones by visiting our website and following us on LinkedIn, X, and YouTube.
Join us in shaping the future of aviation through research-driven innovation.

Funded by the European Union. Views and opinions expressed are however those of the author(s) only and not necessarily reflect those of the European Union or CINEA. Neither the European Union nor CINEA can be held responsible for them.