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ISSN Online: 2377-424X

ISBN Print: 1-56032-797-9

International Heat Transfer Conference 11
August, 23-28, 1998, Kyongju, Korea

NUMERICAL STUDY ON HEAT TRANSFER CHARACTERISTICS OF HELIUM II WITH PHASE TRANSITIONS

Get access (open in a dialog) DOI: 10.1615/IHTC11.3710
pages 219-224

Abstract

A numerical model is proposed to study the forced convective heat transfer in a locally-heated superfluid helium pipeline that is subject to phase transitions: the λ-transition and boiling. The present model basically consists of three conservation equations: mass, momentum and energy equations. To express the heat transfer characteristics of each phase, certain parameters to be added to the equations for homogeneous flow are determined for each phase conditions of helium. One of the parameters indicates the momentum difference between the momentum conservation equations for the homogeneous flow model and the two-fluid model. The other indicates the heat transport by internal convection and heat conduction. The one-dimensional transient numerical code based on the present model has been developed. In order to verify the validity of the present model, the temperature profiles obtained by using the present model are compared with those obtained by the two-fluid model for the case of heat and fluid flow in a superfluid helium pipeline. The validity and limitation of the present model are discussed. Then the heat transfer characteristics of helium flow with phase changes are numerically solved for the case of flow on a pipeline 100cm in length and 3mm in ID which is locally heated at the middle section. It is found that both the internal convection and the forced convection are important in the superfluid helium region while the heat transport by the forced convection plays an important role in other regions.