Meeting global climate targets requires a transition from fossil fuels to sustainable energy carriers, with hydrogen expected to play a key role in sectors that are difficult to electrify directly. However, hydrogen storage remains a major technical challenge due to its low volumetric energy density under ambient conditions and the resulting requirements for high storage pressure, low temperature, or both. Liquid hydrogen (LH₂) offers a high gravimetric and volumetric energy density compared with compressed gaseous hydrogen and is therefore particularly attractive for applications requiring long range, low system mass and compact storage volume, including aviation, aerospace, maritime transport and heavy-duty mobility.
The development and operation of safe, efficient and reliable LH₂ storage systems is challenging because their behaviour is governed by strongly coupled physical phenomena, including cryogenic temperature, heat ingress, pressure build-up, stratification, phase change and two-phase flow. Addressing these effects requires research and development tools that combine representative experimental infrastructure with numerical methods at different levels of fidelity. This contribution presents an integrated experimental and simulation-based approach for the development, validation and optimisation of LH₂ storage systems.
The experimental basis is provided by our Liquid Hydrogen Laboratory, which enables component- and system-level testing under cryogenic hydrogen conditions. The infrastructure is designed with a footprint of approximately 2,500 m² and an on-site LH₂ storage capacity of approximately 4,400 kg at 8–10 bar in a stationary tank. Extraction rates of up to 5,600 kg/h can be supplied directly from the storage tank. A dedicated conditioning vessel with a capacity of 250 kg enables further pressurisation of LH₂ with gaseous hydrogen up to 36 bar and allows extraction rates above 860 kg/h. Controlled mixing of LH₂ and gaseous hydrogen also enables the provision of cryogenic gaseous hydrogen in the range of 50–100 K for component and subsystem tests, for example on valves or venting systems. Automated test cells equipped with data acquisition, customised control strategies and CAx-supported hardware-in-the-loop and software-in-the-loop capabilities support reproducible testing of components, materials and smaller storage systems, while a large outdoor test area enables the assembly and investigation of larger LH₂ systems.
These experimental capabilities are complemented by numerical research and development tools ranging from high-fidelity 3D computational fluid dynamics (CFD) to fast modular system-level simulations. Transient CFD methods are applied to analyse LH₂ refuelling, phase change, pressure build-up, gas–liquid interaction, heat transfer and boil-off behaviour under dynamic operating conditions. These simulations provide detailed insight into local flow and thermal phenomena that are difficult to access experimentally. In parallel, reduced-order and 0D models enable rapid design screening, parameter studies, operational strategy assessment and system integration analyses.
A central element of this toolchain is LH2VPATT, an in-house developed modular 0D thermodynamic simulation tool for LH₂, subcooled LH₂, cryo-compressed hydrogen and two-phase filling and extraction processes. Its modular component database, including tanks, valves, pipes, nozzles, receptacles and pumps, enables the user-friendly assembly of complete storage system topologies and refuelling infrastructures based on real component data. LH2VPATT supports the analysis and optimisation of refuelling and extraction strategies, thermal conditioning concepts and alternative system layouts at low computational cost.
By combining representative LH₂ test infrastructure, high-fidelity CFD and modular 0D thermodynamic system simulation, HyCentA provides a comprehensive development environment for future LH₂ storage technologies. This integrated toolchain supports the design, validation and optimisation of safe, efficient, scalable and application-specific storage systems for aviation, aerospace, maritime transport, heavy-duty mobility and stationary storage infrastructure.

Keywords
liquid hydrogen storage systems|cryogenic testing|thermodynamic system simulation|multiphase CFD|liquid hydrogen infrastructure