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

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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PIV Analysis of Dynamic Velocity Profiles in Non-Newtonian Drilling Fluids Exposed to Oscillatory Motion

Volume 8: Polar and Arctic Sciences and Technology; Petroleum Technology ◽

10.1115/omae2018-77614 ◽

2018 ◽

Author(s):

Maduranga Amaratunga ◽

Roar Nybø ◽

Rune W. Time

Keyword(s):

Low Frequency ◽

Velocity Profiles ◽

Liquid Column ◽

Oscillatory Motion ◽

Velocity Shear ◽

Drilling Fluids ◽

Cross Sectional ◽

Low Frequencies ◽

Wide Range ◽

Dynamic Velocity

Drilling fluids experience a wide range of shear rates and oscillatory motion while circulating through the well and also during the operations for solids control. Therefore, it is important to investigate the influence of oscillatory fields on the velocity profiles, shear rate and resulting rheological condition of non-Newtonian polymers, which are additives in drilling fluids. In this paper, we present the dynamic velocity profiles within both Newtonian (deionized water) and non-Newtonian liquids (Polyanionic Cellulose – PAC) exposed to oscillatory motion. A 15 cm × 15 cm square cross-sectional liquid column was oscillated horizontally with very low frequencies (0.75–1.75 Hz) using a laboratory made oscillating table. The dynamic velocity profiles at the bulk of the oscillating liquid column were visualized by the Particle Image Velocimetry (PIV) method, where the motion of fluid is optically visualized using light scattering “seeding” particles. Increased frequency of oscillations lead to different dynamic patterns and ranges of velocity-shear magnitudes. The experiments are part of a comprehensive study aimed at investigating the influence of low frequency oscillations on particle settling in non-Newtonian drilling fluids. It is discussed, how such motion imposed on polymeric liquids influences both flow dynamics as well as local settling velocities of cuttings particles.

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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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Processing Polymer Melts under Rheo-Fluidification Flow Conditions, Part 1: Boosting Shear-Thinning by Adding Low Frequency Nonlinear Vibration to Induce Strain Softening

Journal of Macromolecular Science Part B ◽

10.1080/00222348.2012.711999 ◽

2012 ◽

Vol 52 (3) ◽

pp. 407-441 ◽

Cited By ~ 8

Author(s):

J. P. Ibar

Keyword(s):

Nonlinear Vibration ◽

Strain Softening ◽

Polymer Melts ◽

Low Frequency ◽

Shear Thinning ◽

Flow Conditions ◽

Processing Polymer

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A Study of Particle Settling in Non-Newtonian Fluids—Part I: A New Method for the Study of Particle Settling in Drilling and Fracturing Fluids

Journal of Energy Resources Technology ◽

10.1115/1.2906002 ◽

1994 ◽

Vol 116 (1) ◽

pp. 10-15 ◽

Cited By ~ 1

Author(s):

L. Jin ◽

M. E. Chenevert

Keyword(s):

Reynolds Number ◽

Drag Force ◽

Force Measurement ◽

Newtonian Fluids ◽

Particle Settling ◽

Number Range ◽

Fracturing Fluids ◽

Wide Range ◽

Good Set ◽

Settling Of Particles

A drag force measurement method is presented which makes it possible to study the settling of particles in transparent and opaque fluids. A dimensionless treatment that takes into account the shear thinning effects of fluids was applied to normalize the measured drag force data. A wide range of particle Reynolds numbers can be covered by this method and a profile of friction factor versus Reynolds number can be established by the proposed dimensionless treatment. An algorithm for the prediction of settling of particles in non-Newtonian fluids was introduced. It can be executed by a computer program. With a good set of experimental data, the settling velocities predicted by the computer model are very close to the measured ones in the fluids tested. This method can be used to study the suspension properties of drilling and fracturing fluids, transparent or opaque. The wide coverage of Reynolds number range simplifies the experiment.

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