The effect of shear thinning and walls on the sedimentation of a sphere in an elastic fluid under orthogonal shear

Padhy, Sourav; Rodriguez, Mauro; Shaqfeh, Eric S. G.; Iaccarino, Gianluca; Morris, Jeffrey F.; Tonmukayakul, N.

doi:10.1016/j.jnnfm.2013.07.007

Cited by 25 publications

(17 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Tanner, Housiadas, and coworkers (194,195) have studied the drag on a sphere, pointing to an added elastic stress contributed by the distortion of streamlines induced by the settling particle. Padhy et al (128,196) perform computations using FENE-P and Giesekus models to mimic a Boger fluid and a guar solution lightly crossslinked with borate (which shows enhanced settling with increasing shear rate in experiments (citation)). Their computations capture the retarded settling observed in experiments, and also capture the result of Housiadas and Tanner (194) when walls bounding the flow are removed (infinite domain).…”

Section: Particle Migrationmentioning

confidence: 99%

“…Their computations capture the retarded settling observed in experiments, and also capture the result of Housiadas and Tanner (194) when walls bounding the flow are removed (infinite domain). Padhy et al (128,196) examine individual contributions to the total drag and highlight the competition between elasticity (which increases frictional drag) and shear thinning (decreasing drag). They further note that these phenomena scale differently with polymer concentration, and a optimum concentration exists to minimize the sedimentation speed (196).…”

Section: Particle Migrationmentioning

confidence: 99%

See 1 more Smart Citation

Complex Fluids and Hydraulic Fracturing

Barbati

Desroches

Robisson

et al. 2016

Annu. Rev. Chem. Biomol. Eng.

165

View full text Add to dashboard Cite

Nearly 70 years old, hydraulic fracturing is a core technique for stimulating hydrocarbon production in a majority of oil and gas reservoirs. Complex fluids are implemented in nearly every step of the fracturing process, most significantly to generate and sustain fractures, and transport and distribute proppant particles during and following fluid injection. An extremely wide range of complex fluids are used: naturally occurring polysaccharide and synthetic polymer solutions, aqueous physical and chemical gels, organic gels, micellar surfactant solutions, emulsions, and foams. These fluids are loaded over a wide range of concentration with particles of varying size, and aspect ratio, and are subjected to a extreme mechanical and environmental conditions. We describe the settings of hydraulic fracturing (framed by geology), fracturing mechanics and physics, and the critical role that non-Newtonian fluid dynamics and complex fluids plays in the hydraulic fracturing process.

show abstract

Section: Particle Migrationmentioning

confidence: 99%

Section: Particle Migrationmentioning

confidence: 99%

Complex Fluids and Hydraulic Fracturing

Barbati

Desroches

Robisson

et al. 2016

Annu. Rev. Chem. Biomol. Eng.

165

View full text Add to dashboard Cite

show abstract

“…On the contrary, the significance of the solid boundaries is well received in the context of particulate viscoelastic flows. Several computational (Ardekani et al 2007; D’Avino et al 2009; Despeyroux and Ambari 2012; Padhy et al 2013) and experimental (Tatum et al 2007; Ardekani et al 2009; Eisenberg et al 2013) investigations have been carried out to shed light on the dynamical behavior of rigid particles moving in close proximity of a solid surface in non-Newtonian fluids. In particular, it is found (Ardekani et al 2007) that in the second-order fluids, a strong attraction force is developed which draws a solid sphere towards the corresponding wall.…”

Section: Introductionmentioning

confidence: 99%

Effect of solid boundaries on swimming dynamics of microorganisms in a viscoelastic fluid

Karimi

Ardekani

2014

Rheol Acta

View full text Add to dashboard Cite

We numerically study the effect of solid boundaries on the swimming behavior of a motile microorganism in viscoelastic media. Understanding the swimmer-wall hydrodynamic interactions is crucial to elucidate the adhesion of bacterial cells to nearby substrates which is precursor to the formation of the microbial biofilms. The microorganism is simulated using a squirmer model that captures the major swimming mechanisms of potential, extensile, and contractile types of swimmers, while neglecting the biological complexities. A Giesekus constitutive equation is utilized to describe both viscoelasticity and shear-thinning behavior of the background fluid. We found that the viscoelasticity strongly affects the near-wall motion of a squirmer by generating an opposing polymeric torque which impedes the rotation of the swimmer away from the wall. In particular, the time a neutral squirmer spends at the close proximity of the wall is shown to increase with polymer relaxation time and reaches a maximum at Weissenberg number of unity. The shear-thinning effect is found to weaken the solvent stress and therefore, increases the swimmer-wall contact time. For a puller swimmer, the polymer stretching mainly occurs around its lateral sides, leading to reduced elastic resistance against its locomotion. The neutral and puller swimmers eventually escape the wall attraction effect due to a releasing force generated by the Newtonian viscous stress. In contrast, the pusher is found to be perpetually trapped near the wall as a result of the formation of a highly stretched region behind its body. It is shown that the shear-thinning property of the fluid weakens the wall-trapping effect for the pusher squirmer.

show abstract

“…By contrast, the non-Newtonian response is not prescribed a prior in our analysis; rather, it emerges from a micromechanical treatment of the nonequilibrium suspension microstructure. Finally, more recent experiments by Tonmukayakul et al (2010) have shown an increase in settling speed with increasing Wi in shear-thinning guar gum solutions, which has been qualitatively captured by the numerical calculations of Padhy et al (2013b). It should be noted that a hard-sphere colloidal dispersion also shear thin at small Pe s [Bergenholtz et al (2002)], with or without hydrodynamic interactions, which may provide a "constitutive explanation" for the prediction of shearenhanced settling in Eq.…”

Section: Probe Motionmentioning

confidence: 66%

“…Numerical calculations by Padhy et al (2013a) (not restricted to small Wi) suggest the discrepancy to arise from the neglect of the effect of side walls by Housiadas and Tanner (2012). Tonmukayakul et al (2010), in contrast, observed an increase in settling rate with increasing Wi in shear-thinning guar gum solutions, which further computations by Padhy et al (2013b) captured. Notably, the shear-driven modification in settling velocity is predicted to be proportional to OðWi 2 Þ at small Wi for a host of constitutive models Tanner (2012, 2014)].…”

Section: Introductionmentioning

confidence: 98%