Berlin 2008 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 26: Fluid dynamics II

DY 26.8: Vortrag

Donnerstag, 28. Februar 2008, 16:00–16:15, MA 001

Boundary induced Spirals in counter-rotating Taylor-Couette flow — •Kerstin Hochstrate, Matti Heise, Jan Abshagen, and Gerd Pfister — Institute of Experimental and Applied Physics, Kiel, Germany

One of the classical hydrodynamic systems for the study of bifurcation events is the flow of a viscous fluid confined in the gap between two concentric rotating cylinders, i.e. Taylor-Couette flow. The focus of our study is the onset of spiral vortex flow as primary instability from basic laminar flow between counter-rotating cylinders with stationary and rotating end plates. Spirals are traveling waves in axial and rotating waves in azimuthal direction having an azimuthal wave number of m = ± 1 in the parameter space studied here. In contrast to many theoretical investigations considering infinite axial length almost all experimental realization of Taylor-Couette flow use stationary rigid end plates confining the flow in axial direction. These end plates are relevant for the dynamical characteristics and the bifurcation behavior of ’global’ spiral vortex flow and even may induce ’localized’ spirals near these ends. We used independently rotating end plates in order to study the stability and the underlying physical mechanism for the onset of ’global’ and ’localized’ spirals.