Nichtinvasive Characterisierung von Transporteigenschaften poröser Medien : dreidimensionale Untersuchungen mit Hilfe der Kernspintomographie

Herrmann, Karl-Heinz

Dissertation / PhD Thesis/Book

Nichtinvasive Characterisierung von Transporteigenschaften poröser Medien : dreidimensionale Untersuchungen mit Hilfe der Kernspintomographie

Herrmann, K.-H. (Corresponding author)FZJ*

2001
Forschungszentrum Jülich GmbH Zenralbibliothek, Verlag Jülich

Jülich : Forschungszentrum Jülich GmbH Zenralbibliothek, Verlag, Berichte des Forschungszentrums Jülich 3915, VIII, 109 p. (2001) = Bonn, Univ., Diss., 2001

Please use a persistent id in citations: http://hdl.handle.net/2128/20237

Report No.: Juel-3915

Abstract: In this thesis a method is presented which gives access to the water flow and the transport of tracer substances an a laboratory scale by using nuclear magnetic resonance imaging. The nuclear magnetic resonance allows a non-invasive and threedimensional observation of the flow and transport properties of a porous media and can be visualized as a time series. Two different NMR methods are employed to columns filled wich model porous media under water saturated conditions. The first method is monitoring the movement of a tracer substance (Ni$^{2+}$) whereas the second method uses a diffusion sensitive NMR sequence to determine the local flow velocities of the water molecules directly without the need of a tracer. Both methods are the basis for further geostatistical analysis like the spatial moments of the tracer concentration and the correlation length of the local water flow velocities. From the spatial concentration moments the macroscopic effective dis persion coefficients are calculated and compared wich the dispersion coefficient determined by conventional methods (break through curves and one-dimensional CDE modeling). These macroscopic dispersion coefficients represent the heterogeneity of the complete columns and include inhomogeneities like packing flaws. In contrast to the tracer monitoring the diffusion sensitive NMR sequence determines the localized dispersive effect of the porous media an a sub-mm scale. To gain the macroscopic effective dispersion an the column scale the three dimensional particle tracking programs TRACE and PARTRACE are employed, based an the experimentally determined local flow velocities.

Note: Record converted from VDB: 12.11.2012
Note: Bonn, Univ., Diss., 2001

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