Publication

Spatiotemporal flow instabilities of wormlike micellar solutions in rectangular microchannels

Bibliographic Details
Summary:Flow velocimetry measurements are made on a non-shear-banding wormlike micellar solution within high-aspect-ratio rectilinear microchannels over a wide range of imposed steady flow rates. At the lowest and highest flow rates tested, Newtonian-like velocity profiles are measured. However, at intermediate flow rates the velocity field never stabilizes on the timescale of the experiments (up to several hours). Here, spatiotemporally dependent jets of high velocity fluid are observed to fluctuate within regions of essentially stagnant fluid. The reason for this flow instability remains undetermined, but it has significant consequences for many industrial applications and also for microfluidic rheometry of complex fluids.
Subject:Ciências exactas e naturais Natural sciences
Country:Portugal
Document type:journal article
Access type:Open
Associated institution:Repositório Aberto da Universidade do Porto
Language:English
Origin:Repositório Aberto da Universidade do Porto
Description
Summary:Flow velocimetry measurements are made on a non-shear-banding wormlike micellar solution within high-aspect-ratio rectilinear microchannels over a wide range of imposed steady flow rates. At the lowest and highest flow rates tested, Newtonian-like velocity profiles are measured. However, at intermediate flow rates the velocity field never stabilizes on the timescale of the experiments (up to several hours). Here, spatiotemporally dependent jets of high velocity fluid are observed to fluctuate within regions of essentially stagnant fluid. The reason for this flow instability remains undetermined, but it has significant consequences for many industrial applications and also for microfluidic rheometry of complex fluids.