Thermo-Structural Behavior of Cryogenic Tanks During Cooldown: A Comparison Between Analytical and Numerical Methods

The study investigated the structural response of a horizontal 316L stainless steel cylinder with torispherical heads, modeled after the demonstrator developed in the Horizon Europe project ALRIGH2T. The tank was idealized as a thin cylindrical shell to capture the effects of internal pressure, and as a Euler-Bernoulli beam to represent gravity and vertically stratified thermal loads. Circumferential thermal stresses were further assessed using two-dimensional thermoelasticity. The overall response was determined by superposition under the assumptions of linear elasticity and temperature-independent material properties.

To validate the analytical approach, the resulting model was benchmarked against detailed LS-DYNA finite element simulations that incorporated internal pressure, idealized liquid-nitrogen thermal gradients, and self-weight. This comparison allowed for assessing both the accuracy and the applicability of the simplified models for preliminary tank design.