Scaling and Instabilities in Bubble Pinch-Off

Burton, Justin; Waldrep, R.; Taborek, P.

doi:10.1103/physrevlett.94.184502

Cited by 164 publications

(214 citation statements)

References 15 publications

Supporting

Mentioning

182

Contrasting

Order By: Relevance

“…The data are well fit with a power law: h min ∝ τ α h , with α h = 0.56 ± 0.03. This is consistent with simulations of Leppinen et al who found α h ≈ 0.55 [25] but exclude α h = 0.50 [21,22,23]. Our data cannot distinguish pure power-law behavior with α h = 0.56 (solid lines in Fig.…”

supporting

confidence: 92%

“…Other singularities [1] have been shown to be sensitive to noise [2]. However, experiment and theory up to now have ignored cylindrical asymmetry [21,22,23,24,25,26], or could not show it to be a generic feature of breakup [14]. We have shown that tilting the nozzle by just 0.07 • detectably alters the outcome of breakup.…”

mentioning

confidence: 79%

“…( 1) where R N is the nozzle radius, σ is the surface tension, ∆ρ is the difference in the densities of the liquid and the air, and g is the gravitational acceleration [23]. The relevant experiment to indicate if surface tension plays a role in the asymptotic dynamics, is to measure the radius of the neck of air at its narrowest part, h min , as a function of τ , the time left to the singularity.…”

mentioning

confidence: 99%

“…Burton et al [23] reported the remarkable observation that instead of proceeding smoothly to zero radius, the [14,24]. Data are taken from multiple pinchoffs, and only data for τ ≤ 230 µs are used for fitting.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Breakup of Air Bubbles in Water: Memory and Breakdown of Cylindrical Symmetry

et al. 2006

View full text Add to dashboard Cite

Using high-speed video, we have studied air bubbles detaching from an underwater nozzle. As a bubble distorts, it forms a thin neck which develops a singular shape as it pinches off. As in other singularities, the minimum neck radius scales with the time until breakup. However, because the air-water interfacial tension does not drive breakup, even small initial cylindrical asymmetries are preserved throughout the collapse. This novel, non-universal singularity retains a memory of the nozzle shape, size and tilt angle. In the last stages, the air appears to tear instead of pinch.PACS numbers: 47.55.db, 47.55.df, 02.40.Xx The delightful tingling felt when drinking carbonated beverages, the glee of children blowing bubbles in a bathtub, and the importance of deep underwater fissures venting gasses into the oceans hint at the richness and significance of bubble formation in determining the texture and composition of our world. However, the process by which a bubble is formed is still full of surprises. A drop or bubble breaks up by forming a neck that thins to atomic dimensions, a process described as an approach towards a singularity where physical quantities such as stress or pressure grow infinitely large. Singularities often organize the overall dynamical evolution of nonlinear systems. Each symmetry in nature implies an underlying conservation law, so that the symmetries of the singularity associated with pinch-off naturally have important consequences for its dynamics. It was previously believed [1,2,3,4,5,6,7,8,9,10,11,12] that the pinching neck of any drop or bubble would become cylindrically (i.e. azimuthally) symmetric in the course of pinch-off. Recently, pinching necks of air in water were observed to lose cylindrical symmetry in the course of detachment [13,14].Here we show that this loss of symmetry is caused by a new form of memory in singular dynamics: even a small asymmetry in the initial conditions is preserved throughout bubble detachment. This novel singularity retains a memory of the nozzle shape, size and tilt angle. The asymmetry can be made so great that the air appears to tear. This symmetry breaking may be important in numerous applications [15,16,17], and for understanding other physical processes which are modeled as the formation of a singularity, such as star or black hole formation [18] and supernova explosions [19]. Thus our experimental observation of the breakdown of cylindrical symmetry in the air bubble demonstrates a new view of dynamical singularities that may be relevant even on a celestial scale.Singularities govern the dynamics in many familiar break-up events, such as the dispersal of oil drops into * Electronic address: nkeim@uchicago.edu vinegar during the making of a salad dressing, or the dripping of water from a leaky faucet. For many fluid pairs -for example, one viscous fluid breaking in a surrounding fluid of high viscosity [7,8,12] -the shape and dynamics of the pinching neck depend solely on the fluid parameters, as the breakup forgets its initial conditions on ...

show abstract

supporting

confidence: 92%

mentioning

confidence: 79%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Breakup of Air Bubbles in Water: Memory and Breakdown of Cylindrical Symmetry

et al. 2006

View full text Add to dashboard Cite

show abstract

“…Simultaneously, a ring of higher pressure develops around the neck of the elongation by the inflow of liquid compressing the neck. Upon neck closure (Burton, Waldrep & Taborek 2005;Thoroddsen, Etoh & Takehara 2007) the liquid between the separated neck parts is accelerated upwards into bubble 2 and downwards through the separated neck part. Immediately after closure, the elongation of bubble 2 still has a sharp, singularity-like tip, and the jet emerging from this tip must be extremely thin and fast.…”

Section: Jet Dynamicsmentioning

confidence: 99%

Dynamics of laser-induced bubble pairs

et al. 2015

View full text Add to dashboard Cite

The interaction of two laser-induced bubbles in bulk water is investigated. The strength and direction of the emerging liquid jets can be controlled by adjusting the relative bubble positions, the time difference between bubble generation, and the laser pulse energies determining the bubble sizes. Experimental and numerical studies are performed for millimetre-sized bubble pairs. Taking bubbles of equal energy, a maximum jet velocity is found for close anti-phase bubbles, i.e. when the second bubble is produced at the maximum volume of the first one and the bubble walls are almost touching and not merging. Under these conditions, one bubble produces a fast jet with a peak velocity of about 150 m s −1 that reaches a distance into the surrounding liquid of at least three times the maximum bubble radius. Collapse of the other bubble results in a slow jet of large mass that rapidly converts into a ring vortex. Correspondingly, the interaction with adjacent structures is dominated either by localized jet impact or by shear stresses extending over a larger area. Furthermore, interactions between micrometre-sized bubble pairs are investigated numerically to understand and predict how the effects of the physical parameters on bubble dynamics would change when the bubbles become smaller. The results are discussed with respect to micropumping and opto-injection.

show abstract

Numerical simulation of microdroplet formation in coflowing immiscible liquids

2007

View full text Add to dashboard Cite

in Wiley InterScience (www.interscience.wiley.com).Monodisperse microdroplets can be formed when a liquid is injected via a capillary needle nozzle into another immiscible coflowing liquid in a microchannel. Such system has been applied in microfluidic devices to produce monodisperse microdroplets with controllable size. In this article, the drop formation in a coflowing system is simulated numerically using a front tracking/finite volume method to investigate the droplet formation mechanism. This numerical method solves a single set of Navier-Stokes equations for both liquid phases on a fixed Eulerian two-dimensional cylindrical coordinate mesh to account for the fluid flow dynamics. The front tracking method is applied to track the movement of the interface between the two immiscible liquids as well as the surface tension force. The simulation results demonstrate that the process of droplet formation in the coflowing immiscible liquids can be reasonably predicted. Two droplet generation modes (namely dripping and jetting), which have been observed in experiments, are successfully produced through the numerical simulations under certain flow conditions. Moreover, the effects of the continuous phase flow speed, viscosity, and the interface tension on the droplet size are investigated. The correlation of the nondimensional droplet size (r

show abstract

Scaling and Instabilities in Bubble Pinch-Off

Cited by 164 publications

References 15 publications

Breakup of Air Bubbles in Water: Memory and Breakdown of Cylindrical Symmetry

Breakup of Air Bubbles in Water: Memory and Breakdown of Cylindrical Symmetry

Dynamics of laser-induced bubble pairs

Numerical simulation of microdroplet formation in coflowing immiscible liquids

Contact Info

Product

Resources

About