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ISSN Online: 2377-424X

ISBN Print: 0-85295-345-3

International Heat Transfer Conference 10
August, 14-18, 1994, Brighton, UK

Unsteady Flow and Heat Transfer in a Channel with Two Ribs Attached to One Wall

Get access (open in a dialog) DOI: 10.1615/IHTC10.2340
pages 73-78

Résumé

A two dimensional numerical computation was performed to investigate the unsteady flow and related heat transfer for a channel with two ribs attached to one wall. Reynolds number, the space between the two ribs and the blockage ratio of the channel were changed in several steps. For some conditions when flow unsteadiness was remarkably observed, instantaneous structures of flow and thermal fields were analyzed in detail. From the results of the analysis, characteristics of the heat transfer under flow unsteadiness is pointed outand how they are produced is also discussed.
A separation shear layer developing from the leading edge of the first rib becomes unsteady in some conditions and it develops into the formation of discrete vortices if the streanwise span of the cavity between the ribs is large enough. They are effective to pump out the hot fluid from the cavity, to feed in the fresh fluid from the main flow into the cavity and therefore to keep the cavity cooler. Each vortex hits the second rib one after another and is broken up into two parts. They exert the washing action respectively on the front and top surfaces of the second rib. and enhance the heat transfer there.