Berlin 2008 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 11: DRG-DPG SYMPOSIUM Rheology III

CPP 11.4: Talk

Tuesday, February 26, 2008, 10:45–11:00, C 264

Flow at the interface of immiscible fluids — Ute Böhme, Frank Bagusat, and •Ulrich Scheler — Leibniz Institute of Polymer Research Dresden, Hohe Str. 6, D-01069 Dresden

Flow in a modified Couette cell with a region of high shear has been investigated at the interface of oil and water. Flow NMR, which is a combination of PFG NMR for the measurement of displacements with NMR imaging has been applied to measure the flow with spatial resolution. NMR contrast has been generated from longitudinal relaxation which enable the measurement of both the spatial distribution and the flow field of each of the components separately. Upon shear in the Couette cell the interface between water and oil becomes bent. Flow measurements reveal, that this bending results from strong axial velocity in the region of high shear. While in homogeneous systems stable eddies in plane are found at the region of high shear, at the interface region between oil and water an eddy out of plane is found as well. The eddies depend on shear reate and viscosity. The out-of-plane eddy is attributed to the difference in viscosity between the two components.