Analytical framework for liquid hydrogen storage tanks in UAVs: Thermal performance validation and structural integrity assessment

The aviation industry faces increasing pressure to transition to environmentally friendly propulsion systems, with hydrogen emerging as a promising solution for unmanned aerial vehicles (UAVs). This study presents a comprehensive analytical framework integrating thermal, structural, fatigue, and impact analyses to evaluate liquid hydrogen storage tanks for UAV applications, addressing the complex challenges in maintaining both thermal performance and structural integrity under demanding operational conditions. Experimental material characterization at cryogenic temperatures was conducted using a 100 kN tensile-fatigue testing system to obtain temperature-dependent properties of SUS316L and Al6061-T6. These properties were incorporated into comprehensive finite element analyses encompassing thermal, structural, fatigue, and drop impact assessments. Thermal analysis validated with experimental testing demonstrated that vapor-cooled shield (VCS) implementation effectively reduced boil-off rate (BOR) by approximately 15 % in small-capacity storage tank. Structural analysis identified critical stress concentration regions under UAV-specific operational loading conditions, demonstrating how this evaluation approach can guide design optimizations to address potential structural vulnerabilities during flight operations. Fatigue analysis confirmed infinite life expectancy exceeding ISO 21029-1 requirements, while drop impact analysis using an ABAQUS user subroutine VUSDFLD - based element deletion approach identified vulnerable components requiring design optimization. This integrated analytical framework establishes new standards for comprehensive safety assessment of liquid hydrogen storage systems in UAV applications, while highlighting the critical balance between thermal isolation requirements and structural integrity demands during flight operations.