“Adapting cryogenic tank technology for commercial aircraft represents some major design and manufacturing challenges”
David Butters, Head of Engineering for LH2 Storage and Distribution at Airbus [1]
Who agree with David Butters’ statement above? I do agree, that’s why this post is up for discussions. In this very short article, we will go through some challenges faced when designing a hydrogen storage for aircrafts.
Designing a LH2 tank isn’t as easy as designing water tank for a fun waterboom in your town. Some challenges and limitations must be adressed:
Geometrical Challenges
Image below (volume part) is just a reminder of the geometrical properties of hydrogen from Part 4. Imagine you have to adjust the airframe for the former avtur tank of 1 litre to hydrogen tank of 3000 litre (gaseous). So then, liquid hydrogen is more feasible by occupying space “only” 4 times more. Still the challenge stands to place hydrogen tank on the aircraft. The shape must be as efficient as possible inside or outside the airframe.
Thermal Challenges
Following the choice of liquid hydrogen, means the hydrogen should be stored in temperature of -253 degree Celcius or 20 Kelvin [3]. The slang word of this definition is stored cryogenically. Therefore, we need to design insulation layers to keep the hydrogen in liquid phase during the flight.
Structural Challenges
The pressure difference between the fluid inside and outside the tank can trigger the explosion or implosion. This is like what happened lately to the Titan, a deep-sea submersible to discover Titanic that lies on the seabed [5]. This is the epitome why structural intergrity plays a crucial part when designing a tank which experiences pressure differences. The pressure inside liquid hydrogen tank is in the range of 1.4-3 bar, compared to the outside pressure of 0.752 bar at altitude of 8000 feet [6]. Hence, the structural design should be carried out.
Airbus has established their engineering centre dedicated for hydrogen tank development in Nantes (France) and Bremen (Germany) [8]. We don’t want to be left behind by them, do we? So, we’re cruising into more detailed design experience of hydrogen tank by adressing each aforementioned challenge ….
MW
If you wanna explore more…
[2] Llewellyn, G., ZEROe: Reducing the climate impact of flying. Airbus.
[3] C. Winnefeld, T. Kadyk, B. Bensmann, U. Krewer, and R. Hanke-Rauschenbach, “Modelling and designing cryogenic hydrogen tanks for future aircraft applications,” Energies, vol. 11, no. 1, p. 105, 2018.
[4] https://newatlas.com/aircraft/hypoint-gtl-lightweight-liquid-hydrogen-tank/
[5] https://www.reuters.com/world/search-intensifies-titanic-sub-with-only-hours-oxygen-left-2023-06-22/
[6] E. J. Adler and J. R. Martins, “Hydrogen-powered aircraft: Fundamental concepts, key technologies, and environmental impacts,” Fuel, vol. 32, p. 7.
[7] https://www.compositesworld.com/articles/stelia-aerospace-composites-advances-hydrogen-storage
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