Title:
Methods and Technologies for Combined Hydrogen-SAF-Operation of Regional and Business Jet Aircraft
Verfahren und Technologien für einen kombinierten Wasserstoff-SAF-Betrieb von Regional- und Geschäftsreiseflugzeugen
Authors:
C. Clemen, R. Eggels, T. Dörr
Abstract:
Hydrogen plays a central role in the decarbonization of aviation as a potentially completely CO2-free alternative to Sustainable Aviation Fuels (SAF). However, numerous technical, logistical, and commercial challenges must be overcome before hydrogen can be introduced to the market. In the last three years, some of the technical challenges, such as the safe and clean direct combustion of hydrogen in an aircraft gas turbine, have already been successfully addressed [1-4]. However, the integration of a liquid hydrogen supply into the engine or airframe, in particular, has not yet reached an acceptable technological level; for example, the necessary pumps are not yet fully developed. Furthermore, the safe handling of liquid hydrogen in aircraft, and especially at airports, is not yet established. The necessary infrastructure worldwide for supplying airports with the required quantities will also not be universally available when the first hydrogen-powered aircraft is ready for market. Therefore, the question arises as to which model is commercially viable for introducing hydrogen into aviation. Based on the challenges mentioned above, it may be sensible to power short-haul aircraft with hydrogen, which could then be stored in gaseous form on board. For medium- and long-haul flights, Sustainable Aviation Fuel (SAF) would be used. However, a viable business case will only emerge if a sufficient number of aircraft can be brought to market. Therefore, it would make sense, particularly in the business travel and regional aircraft markets, to establish products that can operate on both fuels, as these often only serve short distances of up to 1000 nautical miles, but still need to offer customers a range of 4000 nautical miles or more. This is known as "dual-fuel" operation. This concept is being investigated by Rolls-Royce in the research projects Cavendish (EU Clean Aviation), Wotan (Lufo 6, grant number 20M2104A), and Bretuflex (Lufo 6, grant number 20M2237H). This paper examines the operational and technical aspects necessary for dual-fuel operation and outlines and discusses technical solutions at both the aircraft and engine/component levels. Three operating modes are of particular interest: 1. Dual-fuel operation, 2. Switchover operation, and 3. Parallel operation. Each of these scenarios has advantages and disadvantages, as well as technical solutions, which are presented in this paper from the perspective of the engine manufacturer Rolls-Royce.
Event:
Deutscher Luft- und Raumfahrtkongress 2025, Augsburg
Location, Year:
Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn, 2025
Format:
21,0 x 29,7 cm, 6 Pages
Descriptors:
EN: Hydrogen Aircraft gas turbine
Citation:
Clemen, C.; Eggels, R.; Dörr, T. (2025): Verfahren und Technologien für einen kombinierten Wasserstoff-SAF-Betrieb von Regional- und Geschäftsreiseflugzeugen. DGLR Published Conference Papers. Volume 4. (2026). ISSN: 2941-3451. Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V.. (Text). https://doi.org/10.25967/650019. urn:nbn:de:101:1-2511031343336.755283647142.
Publishing Date:
03.11.2025