Para-Hydrogen Narrow Filament Evaporation at Low Temperature

摘要

Undercooling of liquid para-hydrogen (pH_2) below its freezing point at equilibrium (13.8 K) has been shown recently in flowing micro-filaments evaporating in low density background gas [M. Kuhnel et al, Phys. Rev. Lett. 106, 245301 (2011)]. An hydrodynamical model accounting for this process is reported here. Analytical expressions for the local temperature T of a filament, averaged over its cross section, are obtained as a function of distance z to the nozzle. Comparison with the experiment is shown. It is shown also that the thermocapillary forces induce a parabolic profile of velocity across the jet.