HyFive

Load-bearing Type 5 pressure tanks for aviation

The LuFo project HyFive aims to develop a Type-5 hydrogen tank and integrate it into small aircraft as a load-bearing structure.

In order to sustainably reduce CO2 emissions in aviation and thus make a significant impact on climate change it is essential to drastically reduce the need for petroleum-based fuels. The use of hydrogen in fuel cells therefore offers a promising alternative. By using green hydrogen, CO2 emissions can almost be reduced to zero. In the aircraft, the hydrogen can be converted to water through oxidation, generating to directly power electric motors. This enables aircrafts to be powered up to 20% more efficiently than with combustion engines.

However, a major constraint in the use of hydrogen is its safe and efficient storage. As hydrogen is a very light and volatile gas, its storage requires either extreme cooling at temperatures below -253 °C (cryogenic) or high pressure of over 350 bar. The current state of the art is mainly type-IV pressure vessels, which consist of two different layers. The actual vessel is usually made of carbon fibre-reinforced epoxy resin (CF-EP) while the inner liner is made of polyamide, which acts as a permeation barrier for hydrogen. A significant technological advancement is the development of type-V vessels. These could achieve an even greater weight reduction by completely removing the liner. Instead, the outer shell of the tank would take over the task of the permeation barrier. The challenge here, however, is to achieve gas-tightness even under high pressures, as micro cracks can form in the polymer.

In collaboration with aircraft manufacturer APUS, the target of the HyFive project is to develop an innovative hydrogen vessel that is not only lighter than existing storage solutions but can also take on load-bearing functions. Additionally, a thermoplastic matrix is being pursued to offer improved recyclability. This advanced vessel is intended to achieve ranges comparable to those of conventional light aircraft. Improved integration with the aircraft structure and optimized recyclability of the vessel are also key focuses.

For this development, the HyFive project is planning extensive tests and simulations. Permeability on various carbon fibre-reinforced thermoplastics will be measured in order to test their suitability as a vessel shell without a liner. In addition, a simulative and experimental characterization of the mechanical properties under static and dynamic loads will be carried out to ensure that the materials also function reliably as a load-bearing structure in the wing. Finally, prototypes of the type-V vessels will be produced and tested for their mechanical properties, leak tightness and burst pressure. In order to monitor the loads and damage to the vessels during operation, extensive sensors will be installed in and on the tank and linked to a digital twin, which minimizes the maintenance effort and increases safety at the same time.

Field of competence

Industry sectors

Project status

  • Current

Project Partner

Contacts

M.Sc.

Cedric Fuchs

Scientific Staff Design of Composite Structures

Telephone: +49 631 2017 138

cedric.fuchs@leibniz-ivw.de

Funding

The LuFo project 'HyFive – Load-bearing Type-5 pressure tanks for aviation' is funded by the Federal Ministry for Economic Affairs and Climate Action through the German Bundestag (funding reference: 20M2256B).