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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

EXAMINATION OF THE VELOCITY COMPONENTS OF A HIGHLY COMPLEX SWIRLING FLOW

Get access (open in a dialog) DOI: 10.1615/IHTC10.5130
pages 165-170

Resumo

A laboratory scale swirling rig with swirl numbers varying from 3.043 to 1.790 was used to examine the effects of flowrates and swirl numbers upon the size, shape, and position of the precessing vortex core. Also examined was the effect the precessing vortex core had on the reverse flow zone, and the relationship between the two.
It was concluded that the reverse flow zone displaced the central vortex core to create the precessing vortex core. The reverse flow zone would then provide feedback for the precessing vortex core, and precess around the central axis about 30 degrees behind the precessing vortex core (P.V.C.).
The size and position of the P.V.C. was effected by changes in Reynolds number (Re), and any additions of downstream systems to the cyclone would also affect the strength of the P.V.C.
The P.V.C would squeeze and accelerate much of the flow through a constriction set up between the outer limits of the core and of the exit diameter wall.
Spiral engulfment vortices were produced on the outside of the flow and served as the initial entrainment mechanism for external flow.
In terms of heat transfer it is clear that the periodic motion of the P.V.C produces very high velocities close to the wall which can give very significant increases in local heat transfer coefficient.