Particle shear-rate history in a Taylor-Couette column

Book · Sat Dec 31 04:00:00 EST 1994

OSTI ID:110067

Rudman, M; Thompson, M C; Hourigan, K ^[1]

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1. Commonwealth Scientific and Industrial Research Organization, Highett, Victoria (Australia). Division of Building, Construction and Engineering

In previous investigations of shear-rate influence on aggregation processes in Taylor-Couette columns, average shear rates have been determined which were based on either laminar non-vortex flow solutions or numerical solutions of Taylor Vortex flow. correlations between effectiveness of aggregation and shear rate are then made on the basis of this average shear rate. In this study the authors show that the use of this approach must be undertaken with caution. Particle tracking algorithms are coupled with a numerical solution of the fluid flow field to obtain shear histories for several particle densities. It is shown that an average fluid shear rate is not necessarily correlated to the average shear rate to which aggregating particles are subject as they traverse the Taylor-Couette column. It is observed that as the rotation rate (or the non-dimensional parameter known as the Taylor number) is increased beyond the maximum allowed for Couette flow, the percentage of neutrally buoyant particles exposed at some time during their history to large shear rates increases. This point is even more important when buoyant particles are considered.

• OSTI ID: 110067
• Report Number(s): CONF-940659--; ISBN 0-7918-1372-X
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
AGGLOMERATION
COUETTE FLOW
EXPERIMENTAL DATA
FLOW MODELS
FLUID MECHANICS
INCOMPRESSIBLE FLOW
LAMINAR FLOW
PARTICULATES
SEDIMENTATION
SEPARATION EQUIPMENT
SHEAR PROPERTIES
STRAIN RATE
TWO-PHASE FLOW
VORTEX FLOW