Abonnement à la biblothèque: Guest
Page d'accueil Archives Thermal Letter Responsables Réunions à venir Assembly for International Heat Transfer Conferences
International Heat Transfer Conference 12

ISSN: 2377-424X (online)
ISSN: 2377-4371 (flashdrive)

Turbulent, buoyancy-influenced flow and heat transfer in a vertical annulus

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

Tian-Hua Wu
School of Engineering, University of Manchester Manchester, M13 9PL, UK

Zeyuan Xu
Department of Mechanical Aerospace and Manufacturing Engineering UMIST POB 88, Manchester M60 1QD, UK

DOI: 10.1615/IHTC12.3780
6 pages

Résumé

Measurements are reported of local heat transfer coefficients and profiles of velocity and turbulence quantities in the case of water flowing upwards and downwards through a vertical passage of annular cross-section having a uniformly heated inner surface and an adiabatic outer surface. By operating at suitably reduced flow rates, influences of buoyancy could be produced which modified the effectiveness of heat transfer. Systematic enhancement occurred with increase of buoyancy influence in the case of downward flow, where buoyancy opposed the motion. Impairment of heat transfer followed by recovery and enhancement occurred in the case of upward flow, where buoyancy aided the motion. These trends are consistent with those found in earlier studies using uniformly heated circular tubes and can be explained in terms of the influence of buoyancy on turbulence. The measurements of velocity and turbulence made in the course of the present study provide direct confirmation of this explanation of the observed heat transfer behaviour. The work reported here formed part of a programme of generic studies of thermal convection initiated by the UK nuclear industry with a view to providing data for validating CFD codes which are used for simulating buoyancy-influenced flows.

Achat $25.00 Check subscription Déontologie de l'édition scientifique et abus Recommander à mon bibliothécaire Ajouter cette page aux favoris