The CAVENDISH project has set ambitious goals, aiming to utilise new technologies and push the boundaries of existing ones in unprecedented ways. One of the key objectives is to integrate a liquid hydrogen fuel system and hydrogen combustion system onto a Rolls-Royce Pearl family engine.
Introducing a new fuel poses various challenges that need to be addressed. One of these challenges is ensuring safe and controlled operation with hydrogen, especially during transients such as engine start-up and shut-down. Hydrogen flame characteristics differ significantly from conventional fuels, affecting ignition and burning behaviour. Hydrogen ignition has shorter delay times, making preheated H2-air mixtures more susceptible to autoignition. Additionally, the higher flame propagation velocity of hydrogen increases the risk of flame flashback.
Designing of the associated fuel system presents another challenge. Aero-engines must rapidly respond to changing power settings, necessitating the inclusion of rich pilot systems in lean-burn aero-engine combustion systems to ensure stability. Modification of typical aero-engine fuel hydraulic functions is also necessary when transitioning from kerosene to hydrogen.
Methodology
To manage such a challenging task, a holistic integrated process is required to bring together the necessary aspects and robustly manage the associated complexities and decisions along the way. Three major phases will form the project.
Enabling Technologies: This phase focuses on developing and maturing the necessary technologies and subsystems for the project, including advanced simulation models, combustion systems, fuel systems, and tank technology.
Ground Demonstration: Includes integrating of developed systems into donor engine, planning and conducting ground tests. Activities in this phase follow the Advanced Product Quality Planning (APQP) process.
Permit to Fly Strategy: Focuses on the journey to obtain a permit to fly, involving close collaboration with airworthiness agencies and the development of novel requirements for the integration of dual-fuel combustion engines and LH2 fuel systems.
Key Scientific Takeaways:
- Proof of capability of a dual-fuel engine to efficiently and safely operate with kerosene and hydrogen.
- Contribute to the effort of achieving carbon neutrality within the aviation industry by 2050 in line with the European Green Deal.
Funding and cooperation
CAVENDISH (Consortium for the AdVent of aero-Engine Demonstration and aircraft Integration Strategy with Hydrogen) is a collaborative project involving industrial partners such as Dassault Aviation, Industria de Turbo Propulsores, S.A., Deutsches Zentrum für Luft- und Raumfahrt, and Rolls-Royce Deutschland. Calculations for this research were partly conducted on the Lichtenberg high-performance computer of the TU Darmstadt.
