Sedimentation of finite-size particles in quiescent wall-bounded shear-thinning and Newtonian fluids

2020 ◽  
Vol 129 ◽  
pp. 103291
Author(s):  
Dhiya Alghalibi ◽  
Walter Fornari ◽  
Marco E. Rosti ◽  
Luca Brandt
Keyword(s):  
Finite Size ◽  
Shear Thinning ◽  
Newtonian Fluids

Formation of droplet of shear‐thinning non‐Newtonian fluids in a step‐emulsification microdevice

AIChE Journal ◽  
2021 ◽  
Author(s):  
Xiyang Liu ◽  
Ziwei Liu ◽  
Shaokun Jiang ◽  
Chunying Zhu ◽  
Youguang Ma ◽  
...  
Keyword(s):  
Shear Thinning ◽  
Newtonian Fluids

Droplet Formation and Fission in Shear-Thinning/Newtonian Multiphase System Using Bilayer Bifurcating Microchannel

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Yong Ren ◽  
Kai Seng Koh ◽  
Jit Kai Chin ◽  
Jing Wang ◽  
Conghua Wen ◽  
...  
Keyword(s):  
Shear Thinning ◽  
Droplet Formation ◽  
Newtonian Fluids ◽  
Model Systems ◽  
Multiphase System ◽  
Blood Capillaries ◽  
Two Systems ◽  
Flow Through ◽  
Newtonian System ◽  
Droplet Fission

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.

Modelling of Laminar Canonical Flows: Revisit

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.

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

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

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

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.

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

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 )).

scholarly journals Flow of Non-Newtonian Fluids in a Single-Cavity Microchannel

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 836
Author(s):  
Mahmud Kamal Raihan ◽  
Purva P. Jagdale ◽  
Sen Wu ◽  
Xingchen Shao ◽  
Joshua B. Bostwick ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Groundwater Remediation ◽  
Shear Thinning ◽  
Newtonian Fluids ◽  
Fluid Inertia ◽  
Fluid Elasticity ◽  
Wide Range ◽  
Primary Direction ◽  
Flow Through ◽  
Single Cavity

Having a basic understanding of non-Newtonian fluid flow through porous media, which usually consist of series of expansions and contractions, is of importance for enhanced oil recovery, groundwater remediation, microfluidic particle manipulation, etc. The flow in contraction and/or expansion microchannel is unbounded in the primary direction and has been widely studied before. In contrast, there has been very little work on the understanding of such flow in an expansion–contraction microchannel with a confined cavity. We investigate the flow of five types of non-Newtonian fluids with distinct rheological properties and water through a planar single-cavity microchannel. All fluids are tested in a similarly wide range of flow rates, from which the observed flow regimes and vortex development are summarized in the same dimensionless parameter spaces for a unified understanding of the effects of fluid inertia, shear thinning, and elasticity as well as confinement. Our results indicate that fluid inertia is responsible for developing vortices in the expansion flow, which is trivially affected by the confinement. Fluid shear thinning causes flow separations on the contraction walls, and the interplay between the effects of shear thinning and inertia is dictated by the confinement. Fluid elasticity introduces instability and asymmetry to the contraction flow of polymers with long chains while suppressing the fluid inertia-induced expansion flow vortices. However, the formation and fluctuation of such elasto-inertial fluid vortices exhibit strong digressions from the unconfined flow pattern in a contraction–expansion microchannel of similar dimensions.

Sign in / Sign up

Export Citation Format

Share Document