The two-dimensional characteristics of the boiling two-phase flow of liquid
helium in a duct are numerically investigated to realize the further devel
opment and high performance of new cryogenic engineering applications. Firs
t, the governing equations of the boiling two-phase flow of liquid helium b
ased on the unsteady drift-flux model are presented and several flow charac
teristics are numerically calculated, taking into account the effect of sup
erfluidity. Based on the numerical results, the two-dimensional structure o
f the boiling two-phase flow of liquid helium is shown in detail, and it is
found that the vapor gas phase rapidly spreads throughout the inner flow d
uct because of the change of the pressure gradient due to the effect of sup
erfluidity which appears in momentum equations. Next, it is clarified that
the distributions of the void fraction, the velocity field and the instanta
neous streamline of two-phase superfluid helium flow show a tendency differ
ent from those of normal fluid helium because the counterflow of two-phase
superfluid occurs against normal fluid flow. According to these theoretical
results, the fundamental characteristics of the cryogenic boiling two-phas
e flow are predicted. The numerical results obtained would contribute to ad
vanced cryogenic industrial applications.