Development of cryogenic tanks using the Scaled Half-Tank Test

Kurzfassung

Liquid hydrogen (LH₂) storage tanks made from carbon fibre-reinforced polymers (CFRP) offer significant advantages for aerospace applications but at the same time require profound understanding of their thermomechanical behaviour at cryogenic temperatures down to ~20 K. Current validation strategies remain fragmented between material-level coupon testing and full-scale tank validation, leaving a critical gap for intermediate-scale structural assessment. This paper presents a Scaled Half-Tank Test methodology utilizing a 400 mm diameter CFRP specimen to bridge this gap. The experimental test rig features a pressure vessel recipient that isolates internal and external volumes, enabling independent control of thermal gradients and differential pressure. Comprehensive instrumentation, including strain sensors, thermocouples, and optical windows, allows real-time correlation of thermomechanical deformation with permeation behavior. The evaluation strategy employs iterative pressurization under stationary thermal states at ambient and cryogenic conditions. Diffusive transport is characterized through asymptotic leak rate plateaus while damage related onset of leakage is captured by abrupt leak rate increase. The test concept, subsystem functionality and expected permeation profiles are successfully validated by initial tests. Ongoing studies are focusing on detailed assessment of tank sealings, cryogenic sensor sensitivities, and correlation of integral system data with local material models.