Experimental study of enhanced mixing induced by particles in Taylor–Couette flows

Abstract

Local mixing dynamics was recently investigated experimentally in Taylor–Couettesingle-phase flow, thanks to simultaneous Particle Image Velocimetry (PIV) and PlanarLaser-Induced Fluorescence (PLIF) techniques. The results highlighted the influence of thesuccessive flow bifurcations and the role of azimuthal wave states on the dispersion of dyeinjected in Taylor–Couette flows.The present work extends this study to two-phase configurations with spherical solidparticles. The respective effect of particle size and concentration on the vortices size andtransition thresholds between the various flow regimes has been examined thanks to flowvisualizations and PIV measurements. These hydrodynamic features have been comple-mented with PLIF experiments, that revealed a drastic enhancement of mixing due to thepresence of particles regardless of the flow regime, highlighting the existence of significantparticle-induced mixing in Taylor–Couette flows.