2-DIMENSIONAL SHEAR DISPERSION FOR SKEWED FLOWS IN NARROW GAPS BETWEEN MOVING SURFACES

Flows transporting material between nearby moving surfaces are ubiquitous in machinery of all scales and with a variety of geometries. Here a general derivation is given of the effective two-dimensional mixing process in a narrow gap for a solute or miscible fluids. Explicit formulae are given for the shear dispersion tensor in laminar and turbulent (logarithmic velocity profile) flows. It is shown that if improved mixing is required, then the optimum direction for additional boundary motion or stress is at right angles to the primary flow direction. © 1990, Cambridge University Press. All rights reserved.