Nonconventional tow-steered pressure vessels for hydrogen storage

Hydrogen has high gravimetric energy density with accompanying low carbon footprint with potential to replace fossil fuels. Hydrogen at ambient temperature is in the gaseous state and should be stored in pressure vessels that can withstand pressures as large as 70MPa, making their design challenging. Developments in manufacturing techniques for composite structures enable varying the fibre tow trajectory throughout the structure to improve the structural performance. These structures are known as variable stiffness composite structures. This technique has recently been used to develop a design method for suppressing inefficient bending in non-spherical pressure vessels. This study employs the bend-free design method for gaseous hydrogen pressure vessels and investigates the potential advantages of this nonconventional design compared to conventional designs by assessing their Hydrogen Weight Efficiency (HWE). Results show that the HWE of the bend-free variable stiffness pressure vessel is 18.6% larger than the HWE of the best conventional design studied.