Hydrogen is widely seen as one of the most promising pathways towards more sustainable aviation. Yet one important question remains: how can hydrogen be stored on board an aircraft in a way that is both efficient and practical?
A new scientific publication from the TRIATHLON project, “A Thermomechanical Model of On-Board Multi-state Hydrogen Fuel Systems in Aviation”, published in the proceedings of the 2nd Vienna Aviation Days 2025, explores how different hydrogen storage approaches could be combined to support the next generation of hydrogen-powered aircraft.
Why hydrogen storage matters
Unlike conventional aviation fuels, hydrogen can be stored in several different states, each with its own advantages and limitations. Some options offer higher energy density, while others can simplify operations or system integration.
Choosing the most suitable storage solution is therefore not straightforward. Future aircraft may need to balance multiple requirements at once, including weight, available space, system complexity, and mission performance.
This raises an interesting question: rather than relying on a single storage approach, could different hydrogen storage states work together within the same aircraft?
Exploring a more flexible approach
The research presented in this paper investigates the concept of multi-state hydrogen storage, combining tanks operating under different pressure and temperature conditions in a single system.
To better understand how such configurations behave during flight, the authors developed a thermomechanical modelling framework capable of simulating the performance of both single- and multi-tank storage systems.
The model tracks how hydrogen storage systems respond throughout a mission, capturing key phenomena such as thermal loads, pressure variations, and interactions between tanks. This allows researchers to study the behaviour of complex storage architectures and gain insights into their potential benefits and limitations.
Building the foundations for future research
Rather than identifying a “best” storage solution, the work provides a tool for exploring different possibilities and understanding the trade-offs associated with each approach.
As hydrogen aviation technologies continue to evolve, such modelling capabilities can help researchers and engineers evaluate alternative system architectures, support design decisions, and guide future optimisation efforts.
The publication also contributes to the broader objectives of the TRIATHLON project, which is advancing innovative hydrogen powertrain technologies for aviation and helping accelerate the transition towards climate-neutral air transport.
This work was carried out with the support of TRIATHLON partners Delft University of Technology, Dresden University of Technology, and Cryomotive GmbH.
Read the full paper here.
