Abstract
A modified two-fluid model is applied to study flow and heat transfer of superfluid helium in a micro channel with a diameter as small as that of a superleak in a fountain effect pump. Variable properties of superfluid helium and energy dissipations due to the two-fluid mutual friction and the friction at the channel wall are taken into consideration. It is found that the normalfluid component flow is not trivial even in a channel of a diameter of micro meters, and that there exists an optimum diameter which attains the maximum mass flow rate. The flow of superfluid helium through a channel with different temperatures at the ends differs considerably from that of a Newtonian fluid. The strong dependence of the thermodynamic properties on temperature and pressure, as well as the internal-convection mechanism is found to be the causes of the unique flows.
