NMR IMAGING OF VELOCITY PROFILES AND VELOCITY DISTRIBUTIONS IN BEAD PACKS

Citation
Ye. Kutsovsky et al., NMR IMAGING OF VELOCITY PROFILES AND VELOCITY DISTRIBUTIONS IN BEAD PACKS, Physics of fluids, 8(4), 1996, pp. 863-871
Citations number
21
Categorie Soggetti
Mechanics,"Phsycs, Fluid & Plasmas
Journal title
ISSN journal
10706631
Volume
8
Issue
4
Year of publication
1996
Pages
863 - 871
Database
ISI
SICI code
1070-6631(1996)8:4<863:NIOVPA>2.0.ZU;2-B
Abstract
Spatially resolved velocity profiles and spatially nonresolved velocit y distributions of steady flow in a tube and bead packs were measured. Two different NMR experiments were used to measure velocity distribut ions. In one, the velocity histogram was calculated from spatially res olved velocity phase encoded images acquired in a 6 mm bead pack. In t he other, a Fourier how method was used to measure the velocity distri bution directly in a 0.25 mm bead pack. Axial velocity profiles in the pore space of the 6 mm bead pack at Reynolds numbers of 14.9, 29.9, a nd 44.8 proved to be roughly parabolic, with maxima near the pore cent ers. Both NMR methods yielded the same dimensionless velocity distribu tions that contain negative as well as positive velocity components. T he velocity distribution function derived from a bundle-of-tubes-model accounts for the positive part of the velocity distribution. (C) 1996 American Institute of Physics.