by Magnetic Resonance Tomography

Claudia Heinen1, Gisela Guthausen2, Hans Buggisch3

Institute of Mechanical Process Engineering and Mechanics, University of Karlsruhe (TH), Am Fasanengarten, Geb. 50.31; 76131 Karlsruhe

1 claudia.heinen@ciw.uni-karlsruhe.de

2 gisela.guthausen@ciw.uni-karlsruhe.de

3 hans.buggisch@ciw.uni-karlsruhe.de

ABSTRACT

Spatially resolved velocity profiles of steady flow in a two-tube model is measured by MRI (Magnetic Resonance Imaging). The velocity distribution was calculated from these images acquired in a two- tube model with ratio of radii of two. The velocity distribution function derived from the tube model demonstrates the use of MRI to characterize a fluid rheologically. Velocity distributions for three different materials, i.e. water (Newtonian fluid), xanthan gum solution (Power-law fluid), ultrasonic gel (fluid with yield point,) were measured. Quantitative agreement with theory based upon simple constitutive models was obtained in case of water and xanthan in the two-tube model. The velocity distribution function from MRI experiments in principle allows the non-invasive determination of flow behaviour in complicated geometry.

Keywords NMR-Imaging of non-Newtonian fluid flow, velocity distribution function or frequency spectrum, determination of the Power-law exponent in tube-flow