Numerical study on settlement behaviors of slush hydrogen in cryogenic tank

Abstract

Slush hydrogen can be used as a promising propulsion fuel for deep space exploration vehicles because of its more excellent thermodynamic properties compared with liquid hydrogen. To study stratification and settlement characteristics of slush hydrogen in cryogenic tanks, a transient model based on Eulerian–Eulerian two‐fluid method was developed and was verified by experiment data. Many numerical simulations were conducted to determine the influence of settlement, including particle diameter (dp = 0.5–0.015 mm), initial volume fraction of solid hydrogen (αs = 30%–50%), and heat leakage of cryogenic tank (qleak = 15–45 W m−2). It was found that there is a critical particle diameter for settlement of slush hydrogen, which is about 0.02 mm. Meanwhile, a large range of natural convection circulation has been observed in the entire tank. Numerical results of this paper could improve uniform distribution of slush hydrogen for highly efficient storage and application.