Library Subscription: Guest
IHTC DL Home Archives Officers Future meetings Assembly for International Heat Transfer Conferences

STUDIES OF BUOYANCY-INFLUENCED TURBULENT FLOW AND HEAT TRANSFER IN VERTICAL PASSAGES

DOI: 10.1615/IHTC13.p30.240
33 pages

John Derek Jackson
School of Mechanical, Aerospace and Civil Engineering, University of Manchester, Manchester M1 3 9PL, UK

Abstract

A retrospective presentation is made of experimental research carried out over a period of more than four decades by the author and co-workers at Manchester on buoyancy-influenced turbulent flow and heat transfer in vertical passages. Firstly, some experimental results which provided the initial stimulus for the research are discussed. Then, after reviewing the main studies reported on turbulent mixed convection to conventional fluids such as water and air in vertical tubes, the observed effects of buoyancy on heat transfer are summarised and illustrated. Some buoyancy-influenced profiles of velocity and temperature are presented and the effects of buoyancy on turbulence are briefly summarised. A physical explanation is given of the effects of buoyancy on turbulent flow and heat transfer in vertical tubes and a semi-empirical model of mixed convection is described and evaluated in terms of the extent to which it reproduces observed behaviour and correlates experimental data. The special case of mixed convection heat transfer to liquid sodium is considered. Attention is then focussed on the effects of thermal boundary conditions on turbulent mixed convection in vertical tubes and also on heat transfer within a system through which flow is induced naturally. Next, work on turbulent mixed convection in passages of annular cross section is considered in relation to that for tubes. Results which show how buoyancy-induced impairment of heat transfer is affected by rib type roughness are presented. Some measurements of velocity in an annulus made under conditions where heat transfer was strongly affected by buoyancy are discussed. Measurements of heat transfer, velocity and turbulence in a plane passage heated on one side are then presented. Finally, effects of radiant heat transfer which lead to interactions with buoyancy-influenced convection are considered.

IHTC-13 Digital Library

Measurement of fluid temperature with an arrangement of three thermocouples FLOW BOILING OF A HIGHLY VISCOUS POLYMER SOLUTION