Thermal insulation effect and optimized design of VCS for large evaporation liquid hydrogen storage tank

Cryogenic liquid hydrogen storage faces challenges in aerospace due to its extremely high insulation requirements. Vapor-Cooled Shield (VCS) systems offer efficient insulation, which performance is limited by cryogenic fluid evaporation and the absence of standardized collaborative design criteria for non-isothermal operating conditions. In this research a 3D steady-state heat transfer numerical simulation model of SOFI (Spray-On Foam Insulation) coupled with VCS is constructed, to evaluate the impact of the number of VCS tubes, hydrogen flow velocity (0.5–15 m/s), and flow directions. Results indicated that the flow rate dominates insulation performance of VCS, with 5 m/s minimizing heat leakage. Flow direction marginally affects total heat loss (0.410 % variation) and enhances temperature uniformity. Increasing the number of VCS tubes improves circumferential temperature homogeneity and reduces heat leakage, yielding the optimal number of VCS tubes determined to be 3. The findings elucidate multi-parameter synergy in VCS optimization, providing theoretical guidance for advancing thermal management in liquid hydrogen storage/transportation systems.