Radial Distribution of Mass Transfer and Wall Shear Instantaneous Rates in Couette-Taylor Flow

Abstract

This paper presents an experimental investigation of Couette-Taylor system (CTS) characterized by a radius ratio η = 0.97 and an aspect ratio Γ = 150 to study the spatial distribution of instantaneous mass transfer and wall shear rates. Many electrochemical probes were used to measure the local and instantaneous diffusion limited current at different radial positions of the inner wall of the outer fixed cylinder. Two neighboring probes are spaced apart by an angle of 7° on the circumference of the inner wall of the outer cylinder of the CTS. The electrochemical solution used is a Ferri-Ferrocyanure of potassium with 2% of K2SO4 as supporting electrolyte, 40% of glycerin which delays the instabilities apparition, and 2% of Kalliroscope for vortices visualization. The local and instantaneous mass transfer was determined from the diffusion limited current using the Faraday law. The radial distribution of the azimuthal and instantaneous wall shear rate was determined using different approaches for different Taylor numbers. The results of these approaches are illustrated and discussed.