Simulation on vertical wicking behaviors of liquid hydrogen within metallic weaves in terrestrial and microgravity environments

To predict the wicking performance of liquid hydrogen (LH2) in porous screens, we introduced an evaporative wicking model which has been verified by experiments in liquid nitrogen (LN2). The effects of the fluid properties, the gravity level, the superheated degree and the screen structure parameters on the vertical wicking of saturated LH2 were systematically investigated. The wicking in LH2 performs better than that in LN2, presenting higher maximal wicking height and wicking velocity. At lower gravity, the wicking performance is better in whole but much more sensitive to the changes of superheated condition and structure parameters of the screen. The thermal effect of superheated gas region plays a decisive role in wicking behaviors, significantly reducing the wicking velocity and equilibrium height. The effects of permeability and thickness of the screen are obviously different at superheated condition compared to the isothermal cases. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.