کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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609015 | 880613 | 2010 | 7 صفحه PDF | دانلود رایگان |
Via Lattice Boltzmann simulations we show there is a great deal of universality in the reduced mobility of spheres moving along the centre line of capillaries or rectangular microchannels. The reduced mobility follows a generalization of the Haberman–Sayre correlation, which is a function of the degree of confinement, e. This quantity e = dp/De, is defined as the ratio of the particle diameter and the length scale De, which is a weighted mean of the square root of the cross section area DA, and the hydraulic diameter Dh. The force experienced by spheres in pressure driven flow can be described by a generalized Faxen theorem, combined with effective medium theory. This force can be decomposed in a drag force and a pressure gradient force, both inversely proportional to the reduced mobility.
Drag coefficients of a sphere confined in various microchannel collapse to a single master curve, with the data obtained via fully resolved Lattice Boltzmann simulations.Figure optionsDownload high-quality image (113 K)Download as PowerPoint slideResearch highlights
► Drag coefficient collapse to master curve after rescaling.
► Effective medium theory applies to drag in microchannels.
► Faxen theorem generalized to confined spheres.
Journal: Journal of Colloid and Interface Science - Volume 351, Issue 1, 1 November 2010, Pages 43–49