Heat and Mass Transfer Between Two Saturated He II Baths

Abstract

This chapter examines the heat and mass transfer processes between two saturated He II baths. The two baths, formed from two stainless steel cans of 50 mm ID and 660 mm length, are connected at the top and the bottom with two 100 mm long tubes. The bottom tube, with a 5 mm ID, is filled with liquid He II; the top tube, with a 1.3 mm ID, is filled with saturated He vapor. Heat transfer between the two baths is then governed by the counterflow process in the bottom tube and vapor mass transfer process in the top tube. Steady state and dynamic models, based on energy and momentum equations, are presented and agree very well with experimental results. The chapter also demonstrates that the mass transfer process is a far more efficient heat transport mechanism than the counterflow process in vapor/He II two-phase systems.