Design and analysis of a multi-cell subscale tank for liquid hydrogen storage

This paper outlines the structural performance of a conformable pressurizable tank consisting of intersecting spherical shells (multi-cell tank). Multi-cell tanks outrival conventional multiple cylindrical tanks in volumetric efficiency when required to fit in a rectangular envelope in the automotive industry. When pressurized, the multi-cell (or multi-bubble) tank experiences high stress concentrations at the vicinity of the junctions, and thus the concept of effectively reinforcing those regions without adding significant excess weight becomes crucial. Furthermore, when applied for cryogenic medium storage, the heat transfer between different bodies and the generation of respective thermal stresses in such vessels makes the solution more complicated. In this paper the effect of the i) fiber-reinforced materials at the membrane and ii) unidimensional carbon tows at the intersections on the structural integrity of the tank is analysed for different loading scenarios. An operating window for the proposed tank configuration under the given loading scenario is established indicating the safe zone where the tank can operate.