Effect of storage conditions on the characteristics of cryogenic hydrogen jet dispersion.

The present study examines the effect of storage conditions on the characteristics of cryogenic hydrogen jets released into the atmosphere, relevant to an accidental leakage scenario during storage or transportation. The compressible Reynolds-Averaged Navier–Stokes equations, coupled with the Peng–Robinson equation of state for hydrogen-air mixtures, are solved for a range of operating conditions (storage pressures from 3 – 7 bar and storage temperatures of 50 – 70 K). Flow structures in the near-orifice and self-similar regions are analysed, showing that the presence of shock waves creates conditions favourable for possible condensation of hydrogen and air. In the self-similar region, decay laws based on the shock exit conditions are proposed, demonstrating a slower decay of centreline temperature in comparison to hydrogen concentration and velocity. Additionally, a universal relationship between the centreline mole fraction of hydrogen and temperature is observed, explained using an adiabatic mixing model. [Display omitted] • Numerical simulations of cryogenic hydrogen jet dispersion are performed. • Shock waves in the near-orifice region create conditions conducive to condensation of air. • Scaling of far-field flow quantities using shock exit conditions is more appropriate than using orifice exit conditions. • A universal relationship between the centreline mole fraction of hydrogen and temperature is found. • The found universal relationship can be explained by considering adiabatic mixing between hydrogen and air. [ABSTRACT FROM AUTHOR]