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Entry effects in the open thermosyphon

Published online by Cambridge University Press:  28 March 2006

B. W. Martin
Affiliation:
Department of Mechanical Engineering, Imperial College of Science and Technology, London
F. C. Lockwood
Affiliation:
Department of Mechanical Engineering, Imperial College of Science and Technology, London

Abstract

In this paper flow-visualization techniques are used to study the flow instability which occurs at the orifice in the free convection open thermosyphon. The influence of the shape of the orifice on the measured heat transfer of the system is also studied under both laminar and turbulent conditions. The dominant mode of penetration of the hot stream by the cold fluid entering at the base of the reservoir is found to instigate a mixing region at the orifice. In turbulent flow this spreads into and eventually fills the tube as the Rayleigh number is increased. In such circumstances a sharp-edged orifice appears to give better overall heat transfer than a rounded orifice.

Type
Research Article
Copyright
© 1964 Cambridge University Press

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