Thermal Mixing of Shear-Thinning and Newtonian Fluids in a T-Channel Using Impinging Streams

With a novel platform of bilayer polydimethylsiloxane microchannel formed by bifurcating junction, we aim to investigate droplet formation and fission in a multiphase system with complex three-dimensional (3D) structure and understand the variations in mechanism associated with droplet formation and fission in the microstructure between shear-thinning/Newtonian system versus Newtonian/Newtonian system. The investigation concentrates on shear-thinning fluid because it is one of the most ubiquitous rheological properties of non-Newtonian fluids. Sodium carboxymethyl cellulose (CMC) solution and silicone oil have been used as model fluids and numerical model has been established to characterize the shear-thinning effect in formation of CMC-in-oil emulsions, as well as breakup dynamics when droplets flow through 3D bifurcating junction. The droplet volume and generation rate have been compared between two systems at the same Weber number and capillary number. Variation in droplet fission has been found between two systems, demonstrating that the shear-thinning property and confining geometric boundaries significantly affect the deformation and breakup of each mother droplet into two daughter droplets at bifurcating junction. The understanding of the droplet fission in the novel microstructure will enable more versatile control over the emulsion formation and fission when non-Newtonian fluids are involved. The model systems in the study can be further developed to investigate the mechanical property of emulsion templated particles such as drug encapsulated microcapsules when they flow through complex media structures, such as blood capillaries or the porous tissue structure, which feature with bifurcating junction.

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Modelling of Laminar Canonical Flows: Revisit

Volume 1: Symposia, Parts A and B ◽

10.1115/fedsm2012-72376 ◽

2012 ◽

Author(s):

Kofi Freeman K. Adane ◽

Mark F. Tachie

Keyword(s):

Three Dimensional ◽

Shear Thinning ◽

Secondary Flows ◽

Newtonian Fluids ◽

Navier Stokes ◽

Jet Flows ◽

Wall Jet ◽

Navier Stokes Equation ◽

Incompressible Navier Stokes Equation ◽

Insight Into

Three-dimensional laminar lid-driven and wall jet flows of various shear-thinning non-Newtonian and Newtonian fluids were numerically investigated. The complete nonlinear incompressible Navier-Stokes equation was solved using a collocated finite-volume based in-house CFD code. From the results, velocity profiles at several locations, jet spread rates, secondary flows and vorticity distributions were used to provide insight into the characteristics of three-dimensional laminar canonical flows of shear-thinning non-Newtonian and Newtonian fluids.

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Influence of low-frequency oscillatory motion on particle settling in Newtonian and shear-thinning non-Newtonian fluids

Journal of Petroleum Science and Engineering ◽

10.1016/j.petrol.2020.107786 ◽

2021 ◽

Vol 196 ◽

pp. 107786

Author(s):

Maduranga Amaratunga ◽

Herimonja A. Rabenjafimanantsoa ◽

Rune W. Time

Keyword(s):

Low Frequency ◽

Shear Thinning ◽

Newtonian Fluids ◽

Oscillatory Motion ◽

Particle Settling

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Molecular dynamics simulation on shear thinning characteristics of non-Newtonian fluids

Acta Physica Sinica ◽

10.7498/aps.70.20202116 ◽

2021 ◽

Vol 70 (12) ◽

pp. 124701-124701

Author(s):

YANG Gang ◽

◽

ZHENG Ting ◽

CHENG Qi-Hao ◽

ZHANG Hui-Chen

Keyword(s):

Molecular Dynamics ◽

Molecular Dynamics Simulation ◽

Shear Thinning ◽

Newtonian Fluids ◽

Dynamics Simulation

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A Rational Friction Factor Correlation for Laminar Fully-Developed Pipe Flows of Shear-Thinning Non-Newtonian Fluids

Journal of Fluids Engineering ◽

10.1115/1.4051576 ◽

2021 ◽

Author(s):

Robert Brewster

Keyword(s):

Shear Rate ◽

Friction Factor ◽

Power Law ◽

Fluid Model ◽

Shear Thinning ◽

Newtonian Fluids ◽

Cross Model ◽

Pipe Flows ◽

Design Calculations ◽

Friction Factor Correlation

Abstract A friction factor correlation for laminar, hydrodynamically fully-developed pipe flows of shear-thinning non-Newtonian fluids is derived through analysis and asymptotic considerations. The specific non-Newtonian fluid model used is the Extended Modified Power Law (EMPL) model, which is functionally equivalent to the Cross model. The EMPL model spans the entire shear rate range from the low to the high shear rate Newtonian regions, and includes the intermediate shear rate power law region. The friction factor correlation has an explicit form and is a function of three dimensionless parameters, making it well-suited to design calculations. The overall accuracy of the correlation is 6.6%, though it is much better in most cases. Graphical results for the correlation, and deviations with respect to high-accuracy numerical calculations are presented and discussed.

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Computational simulation of mixing flow of shear thinning non-Newtonian fluids with various impellers in a stirred tank

Chemical Engineering and Processing - Process Intensification ◽

10.1016/j.cep.2015.04.009 ◽

2015 ◽

Vol 93 ◽

pp. 66-78 ◽

Cited By ~ 21

Author(s):

Jaime Sossa-Echeverria ◽

Fariborz Taghipour

Keyword(s):

Computational Simulation ◽

Shear Thinning ◽

Newtonian Fluids ◽

Stirred Tank

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Capillary imbibition of non-Newtonian fluids in a microfluidic channel: analysis and experiments

Proceedings of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rspa.2020.0496 ◽

2020 ◽

Vol 476 (2242) ◽

pp. 20200496

Author(s):

Srinivas R. Gorthi ◽

Sanjaya Kumar Meher ◽

Gautam Biswas ◽

Pranab Kumar Mondal

Keyword(s):

Early Stage ◽

Microfluidic Channel ◽

Shear Thinning ◽

Newtonian Fluids ◽

Experimental Results ◽

Scaling Analysis ◽

Theoretical Understanding ◽

Link Type ◽

Shear Thinning Fluids ◽

Capillary Dynamics

We have presented an experimental analysis on the investigations of capillary filling dynamics of inelastic non-Newtonian fluids in the regime of surface tension dominated flows. We use the Ostwald–de Waele power-law model to describe the rheology of the non-Newtonian fluids. Our analysis primarily focuses on the experimental observations and revisits the theoretical understanding of the capillary dynamics from the perspective of filling kinematics at the interfacial scale. Notably, theoretical predictions of the filling length into the capillary largely endorse our experimental results. We study the effects of the shear-thinning nature of the fluid on the underlying filling phenomenon in the capillary-driven regime through a quantitative analysis. We further show that the dynamics of contact line motion in this regime plays an essential role in advancing the fluid front in the capillary. Our experimental results on the filling in a horizontal capillary re-establish the applicability of the Washburn analysis in predicting the filling characteristics of non-Newtonian fluids in a vertical capillary during early stage of filling (Digilov 2008 Langmuir 24 , 13 663–13 667 ( doi:10.1021/la801807j )). Finally, through a scaling analysis, we suggest that the late stage of filling by the shear-thinning fluids closely follows the variation x ~ t . Such a regime can be called the modified Washburn regime (Washburn 1921 Phys. Rev. 17 , 273–283 ( doi:10.1103/PhysRev.17.273 )).

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