An Isaac Newton Institute Workshop

Developments in Experimental Pattern Formation

Phase diagram of patterns in Couette-Taylor flow of dilute polymer solutions: co-dimension two and three points.

Author: Victor Steinberg (Weizmann Institute of Science)

Abstract

Phase diagrams of the flow states in Couette-Taylor flow of dilute polymer solutions as a function of three controlled parameters, namely the Reynolds number, the elasticity parameter, and the reduced polymer contribution to viscosity, that is proportional to the polymer concentration, are studied in detail. Flow visualization reveals that the Couette flow becomes unstable simultaneously either to one, two or three flow patterns depending on the location in the control parameter space. We investigate the character of flow motion in different patterns and the mechanism and type of transitions between different patterns using laser Doppler velocimetry.