Optimization of Cryogenic Hydrogen Storage Tanks for Aviation Applications

Sammanfattning

Liquid hydrogen (LH₂) is a promising candidate for future aviation due to its high energy density and low environmental impact. However, its storage poses significant engineering challenges, particularly in maintaining structural integrity while minimizing weight. This thesis aims to design and optimize a cryogenic LH₂ tank for aviation applications and associated supporting elements, focusing on strength, weight efficiency, and manufacturability. A cylindrical tank with spherical end caps was modeled using Aluminum Alloy 2219-T87, chosen for its high yield strength and favorable cryogenic properties. The design process involved a literature review, 3D modeling in SolidWorks, and Finite Element Method (FEM) simulations to evaluate stress distribution under an internal pressure of 20 bar, giving a safety factor of 4. Simulations showed that a standalone tank with 5mm wall thickness could safely withstand the pressure, with maximum von Mises stress staying well below the material’s 395 MPa yield strength. Additional structural supports in the form of a cage-like concept were also tested to explore the potential for thinner tank walls in the hopes of reducing overall weight while keeping structural integrity. However, results showed that support elements often introduced stress concentrations, slightly increasing overall stress levels. The study concludes that although external reinforcement can aid stress distribution, its impact on peak stress must be carefully managed.