Theoretical modeling of diffusion clouds of liquid hydrogen spilling in crosswind field with atmospheric inversion layer

Abstract

A theoretical model was developed to predict the diffusion process of hydrogen clouds in a crosswind field with an atmospheric inversion layer in this work to evaluate the safety of liquid hydrogen spills. The theoretical model was verified by the experimental results carried out by NASA. The results show that the maximum deviation of diffusion cloud centerline heights of the theoretical model and experiments is 8.92%. The mechanism of the inversion layer suppressing cloud rise is revealed from the theoretical model, atmospheric temperature gradient is closely related to the air density gradient. Compared to the case without atmospheric inversion layer, the cloud height decreases by 2.60%, 5.22%, and 8.70% and the cloud concentration increases by 6.20%, 12.78%, and 22.30% for the temperature gradient of 0.03, 0.06 and 0.10 K/m, respectively. The velocity of crosswind is 1.7 m/s, 2.7 m/s, 3.6 m/s, and 6.0 m/s in the temperature gradient of 0.10 K/m inversion layer environment, the height of the cloud is 34.77 m, 24.05 m, 16.83 m, and 11.16 m, and the hydrogen concentrations of the cloud centerline are 10.22%, 13.67%, 17.54%, and 28.92%, respectively. Therefore, it is significant to consider the crosswind field and atmospheric inversion layer for liquid hydrogen diffusion.