Bending-filament model for the buckling and coiling instability of a viscous fluid rope

Nagahiro, Shin Ichiro; Hayakawa, Yoshinori

doi:10.1103/physreve.78.025302

Cited by 8 publications

(3 citation statements)

References 16 publications

(31 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, deceleration of ‘viscous threads’ by means of diverging of the focusing channel is shown to induce ‘viscous buckling instabilities’, leading to formation of periodic folding threads 21 , 24 , 25 , similar to the case of a viscous liquid falling on a solid surface 26 . Furthermore, offsetting the viscous core flow from the middle of the focusing channel by means of applying asymmetric sheath flow rates is shown to induce sinuous perturbations in the direction transverse to the flow, which eventually leads to disintegration of the ‘viscous thread’ into isolated ‘viscous swirls’ 22 .…”

Section: Introductionmentioning

confidence: 99%

Dynamics of high viscosity contrast confluent microfluidic flows

Kurdzinski

Gol

Hee

et al. 2017

Sci Rep

View full text Add to dashboard Cite

The laminar nature of microfluidic flows is most elegantly demonstrated via the confluence of two fluids forming two stable parallel flows within a single channel meeting at a highly stable interface. However, maintenance of laminar conditions can become complicated when there is a large viscosity contrast between the neighbouring flows leading to unique instability patterns along their interface. Here, we study the dynamics of high viscosity contrast confluent flows – specifically a core flow made of highly viscous glycerol confined by sheath flows made of water within a microfluidic flow focusing system. Our experiments indicate the formation of tapered core structures along the middle of the channel. Increasing the sheath flow rate shortens the tapered core, and importantly induces local instability patterns along the interface of core-sheath flows. The dynamics of such tapered core structures is governed by the intensity of instability patterns and the length of the core, according to which the core structure can experience stable, disturbed, broken or oscillated regimes. We have studied the dynamics of tapered core structures under these regimes. In particular, we have analysed the amplitude and frequency of core displacements during the broken core and oscillating core regimes, which have not been investigated before.

show abstract

Section: Introductionmentioning

confidence: 99%

Dynamics of high viscosity contrast confluent microfluidic flows

Kurdzinski

Gol

Hee

et al. 2017

Sci Rep

View full text Add to dashboard Cite

show abstract

“…17 For short intervals of time, 18 the elastic-like behavior of slender viscous structures has been investigated in situations as diverse as the viscous catenary, 19,20 conical singularities 21 and rippling instabilities 22,23 of thin viscous sheets, and the buckling of viscous fluid ropes falling onto a surface. [24][25][26][27][28][29][30][31] The shape of viscous folds has also received attention in the context structural geology with focus on phenomena such as ramp faulting [32][33][34] and subduction. 35,36 Analyses of the mechanism of layer-parallel shortening of viscous sheets embedded in viscous media are sometimes used to estimate the viscosity contrast between layered rocks.…”

Section: Introductionmentioning

confidence: 99%

Folded micro-threads: Role of viscosity and interfacial tension

2011

View full text Add to dashboard Cite

The shape and evolution of periodically folded threads are experimentally examined in a microfluidic network. The fluidic system is designed for the production and lubricated transport of very uniform folds. To investigate the influence of viscosity and interfacial tension on buckling deformations, multiphase flows are scrutinized using both miscible and immiscible fluid pairs. The parameters used to analyze folding morphologies include thread diameter, arc-length, fold amplitude, and wavelength. When fluids are immiscible, the onset of viscous folding is characterized as a function of the capillary number and the phenomenon of "capillary unfolding" where a corrugated thread straightens along the flow direction is demonstrated. The spatial transition from folding to coiling-like flow behavior of high-viscosity capillary threads is also shown.

show abstract

“…Several other related problems of interest have been studied since then; for example, the coiling of elastic ropes 23 , instabilities in dragged viscous threads 24 , and the meandering instability of viscous threads 25 . Lastly, a new one dimensional model has been proposed by Nagahiro and Hayakawa 26 , where they obtain many of the observed features of viscous coiling from a simplified one dimensional flow model.…”

Section: Introductionmentioning

confidence: 99%

Nonlinear Dynamics of Coiling in Viscoelastic Jets

Majmudar,

Varagnat,

Hartt

et al. 2010

Preprint

View full text Add to dashboard Cite

Instabilities in free surface continuous jets of non-Newtonian fluids, although relevant for many industrial processes, remain less well understood in terms of fundamental fluid dynamics. Inviscid, and viscous Newtonian jets have been studied in great detail; buckling instability in viscous jets leads to regular periodic coiling of the jet that exhibits a non-trivial frequency dependence with the height of the fall. Very few experimental or theoretical studies exist for continuous viscoelastic jets beyond the onset of the first instability. Here, we present a systematic study of the effects of viscoelasticity on the dynamics of free surface continuous jets of surfactant solutions that form worm-like micelles. We observe complex nonlinear spatio-temporal dynamics of the jet and uncover a transition from periodic to doubly-periodic or quasi-periodic to a multi-frequency, possibly chaotic dynamics. Beyond this regime, the jet dynamics smoothly crosses over to exhibit the "leaping shampoo effect" or the Kaye effect. This enables us to view seemingly disparate jetting dynamics as one coherent picture of successive instabilities and transitions between them. We identify the relevant scaling variables as the dimensionless height, flow rate, and the elasto-gravity number and present a regime map of the dynamics of the jet in terms of these parameters.

show abstract

Bending-filament model for the buckling and coiling instability of a viscous fluid rope

Cited by 8 publications

References 16 publications

Dynamics of high viscosity contrast confluent microfluidic flows

Dynamics of high viscosity contrast confluent microfluidic flows

Folded micro-threads: Role of viscosity and interfacial tension

Nonlinear Dynamics of Coiling in Viscoelastic Jets

Contact Info

Product

Resources

About