Configuration effect of superfluid helium channel on the lambda-transitionheat flux

Effects of channel of superfluid helium (He II) on heat transport character istics, especially on the h-transition heat flux and temperature rise at th e channel end, are investigated experimentally and numerically. The ends of the channel are kept open to an He II bath under the atmospheric pressure condition. Supply of heat to the channel results in temperature rise at the channel end. This temperature rise increases with an increase in aspect ra tio of the channel. The increase in temperature rise leads to a decrease in the h-transition heat flux. The temperature rise and the h-transition heat flux are estimated by solving two-dimensional heat transport equation cons idering not only the channel but also the He II bath. The results of the pr esent study indicates that the temperature distribution in the He II channe l is affected by two- or three-dimensional heat flow around the channel end , especially for a channel having larger aspect ratio. (C) 2001 Elsevier Sc ience Ltd. All rights reserved.