Spread of hydrogen vapor cloud during continuous liquid hydrogen spills

Abstract The spread of hydrogen vapor cloud during continuous liquid hydrogen spills is numerically investigated. Comparison between terminated and continuous spills has also been carried out. The two-phase flow is predicted by Mixture model and Realizable k-e turbulence model in ANSYS FLUENT. The flammable vapor cloud reaches a steady state with little changes in dimension and volume during continuous spills. Spill rate and wind speed is positively related with the maximum length of the flammable cloud, while the influence of ambient ground temperature is not obvious. Since the moment of spill termination, the length and height of the flammable cloud continue to develop along the continuous trajectory for certain duration, while the volume of the hydrogen vapor cloud deviates instantly. The present work deepens the understanding on continuous liquid hydrogen spills, and provides guidance for determining the safe stand-off distance.