Torsion estimation of particle paths through porous media observed by in-situ time-resolved microtomography.
The torsion distribution of cell paths in two-phase flow of a cell suspension through a porous medium is an important quantity for chromatographic processes. It can be estimated from cell tracking in sequences of three-dimensional images of a suspension pumped through the medium, where the images are acquired by in-situ time-resolved microtomography using synchrotron radiation and inline phase contrast modus. This contribution presents a new method for estimating path torsion from discrete positions, where the estimation is based on an appropriate discretization of the differential-geometric formula of the torsion of a space curve. Investigations performed for an alcoholic suspension of silica gel particles pumped through a partially open polyurethane foam show that the shape of the inner surface of the foam has a considerable impact on the particle paths. It turns out that the variance of the torsion for slow particle moving close to the surface is a half order of magnitude smaller than that of fast particles, which underlines the importance of torsion for filter efficiency.
CRAN (Université de Lorraine and CNRS), 2 avenue de la Forêt de Haye 54516 Vandœuvre-lès-Nancy, France.|University of Applied Sciences, Darmstadt, Germany.
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C
Blankenburg
European Synchrotron Radiation Facility, Grenoble, France.
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A
Rack
CRAN (Université de Lorraine and CNRS), 2 avenue de la Forêt de Haye 54516 Vandœuvre-lès-Nancy, France.
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C
Daul
University of Applied Sciences, Darmstadt, Germany.
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J
Ohser
3D image processing; Chromatography; X-ray phase contrast; synchrotron radiation; two-phase flow