Newtonian and Non‐Newtonian Flows in Microchannels: Inline Rheological Characterization

Abstract

Micro-particle image velocimetry (micro-PIV) is a quantitative full-field technique for the velocity measurement for flows in microfluidics. The flow fields of both Newtonian and non-Newtonian fluids in microchannels were investigated by micro-PIV. The velocity profiles in various polymethyl methacrylate square microchannels were measured. Polyacrylamide aqueous solutions with different concentrations served as non-Newtonian fluids. Two viscous Newtonian fluids were also employed to serve as reference, in particular to validate a lattice Boltzmann (LB) simulation. Satisfactory flow measurements could be realized by the micro-PIV technique. The experimental velocity profile compares well with the LB simulation and an approximate solution. The experimentally measured velocity profile can lead to the quantification of the flow index of non-Newtonian fluids as an inline rheological characterization.

Thermo‐Rheology of a Proline‐Based Surface‐Active Ionic Liquid: Mixtures with Water and n‐Octane

“…S4 shows the viscoelastic behavior of the binary systems in terms of tan d (G /G ). The magnitudes of both moduli are consistent with those found for other surfactant IL [11]. The G and G values increased with increasing frequencies and decreased with increasing solvent content, which is in good agreement with the steady-shear measurements.…”

“…This means that the tested binary mixtures displayed a typical liquid-like behavior [25]. The magnitudes of both moduli are consistent with those found for other surfactant IL [11].…”

“…1). The apparent viscosity values agree with those evaluated for other non-Newtonian SAIL like 1-butyl-3-methyl-imidazolium DS ([C 4 mim]DS) [10], and shear-thinning IL [11,12]. The return flow curve did not match with the outgoing curve.…”

Assessing Blending of Non‐Newtonian Fluids in Static Mixers by Planar Laser‐Induced Fluorescence and Electrical Resistance Tomography

“…A number of measurement techniques have been applied for monitoring fluid characteristics in inline flows. Nuclear magnetic resonance (NMR) and ultrasonics were applied to estimate rheological parameters of non‐Newtonian fluids (aqueous solutions of Carbopol 940 and Carbopol EZ‐1, respectively) in pipelines in real time, while micro‐PIV was applied in determining the velocity profile of both non‐Newtonian and Newtonian fluids in laminar regime .…”

Escoamento Viscoelástico Através De Microcanais Com Constrição

“…b) Comparação do índice de escoamento n obtido através da técnica de micro-PIV e do rêometro para 6 soluções de PPAm realizado por Fu et al (2015) Figura 18 -Queda de pressão normalizada em função de Weissenberg para três soluções de PEO (PM=2x10 6 g/mol) realizado por Rodd et al (2005) Figura 19 -O diagrama Re vs. Wi mostra um resumo dos diferentes regimes de escoamento para três soluções de PEO (El=3,8, El=8,4 e El=89) realizado por Rodd et al (2005) Figura 20 -Queda de pressão normalizada em função de Weissenberg para quatro soluções de PEO (C=0,075% em peso) realizado por Rodd et al (2007) Figura 21 -Visualização do escoamento da solução de PEO (concentração em peso de glicerina/água C=45%) na entrada da constrição. a) Linhas de tinta.…”