KINETIC MODEL FOR HEAT TRANSFER IN HELIUM II,

Abstract

A model is proposed for the heat transfer in helium II when the net mass transfer is zero and the temperatures are constant. It is assumed that heat is transferred by two processes: (1) by the force coupling between atoms which is the ordinary heat conduction process in solids and (2) by transfer of atoms along with their associated energies. The heat transferred by process (1) is a small fraction of the total except at very low temperatures and is not dealt with here. It is assumed that the transfer of atoms is accomplished in some fashion which maintains at least a relatively constant microscopic density. The number of thermally excited (normal) atoms leaving an area is assumed to be proportional to thermomechanical pressure. As far as the heat transfer is concerned, only those normal atoms leaving the area which are accompanied by returning thermally unexcited (super) atoms are important. Assumptions are made concerning the probabilities for a moving normal atom to be accompanied by a return super atom in wide and in narrow channels. The heat current is calculated as a function of thermomechanical pressure and temperature and is found to agree with experimental results. A brief discussion is given of the relationship of this model to some existing theories of helium II.

Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1955
Accession Number
AD0075425

Entities

People

  • Charles A. Reynolds

Organizations

  • University of Connecticut

Tags

Communities of Interest

  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Couplings
  • Energy
  • Heat Transfer
  • Low Temperature
  • Mass Transfer
  • Probability

Readers

  • Mathematics or Statistics
  • Molecular Photonics/Laser Physics
  • Theoretical Analysis.