Heat transfer through an extended surface containing He II

A semi-analytic solution for the heat transfer process between a He II pres surized bath and a saturated tube-type hear exchanger is presented. The pro blem is modeled with an extended surface heat transfer formulation analogou s to that in conventional conduction. The process is governed by Kapitza co nductance and counter flow within the bulk fluid in the tube. The resulting nonlinear differential equation may be integrated for the special case of constant properties, yielding a simple solution applicable to design and an alysis of practical heat exchangers.