Physics of liquid jets

Eggers, Jens; Villermaux, Emmanuel

doi:10.1088/0034-4885/71/3/036601

Cited by 1,552 publications

(1,247 citation statements)

References 539 publications

Supporting

Mentioning

1,118

Contrasting

Unclassified

Order By: Relevance

“…The experiments show that breakup lengths increase with injection velocity for small injection velocities and then reduce for larger velocities before eventually levelling off (see figure 13 of Hiroyasu et al 1982 which is reproduced as figure 1 here). In the comprehensive review paper by Eggers & Villermaux (2008) the reducing breakup length for larger velocities is explained by the thinning shear velocity at the edge of the jet, but no explanation is given for the rise in the breakup length for small velocities. In this paper we show that the increasing breakup length for small velocities could be due to the value of the fluid velocity at the fluid interface within the shear layer increasing with velocity.…”

Section: Introductionmentioning

confidence: 99%

Stability analysis and breakup length calculations for steady planar liquid jets

et al. 2010

View full text Add to dashboard Cite

This study uses spatio-temporal stability analysis to investigate the convective and absolute instability properties of a steady unconfined planar liquid jet. The approach uses a piecewise linear velocity profile with a finite-thickness shear layer at the edge of the jet. This study investigates how properties such as the thickness of the shear layer and the value of the fluid velocity at the interface within the shear layer affect the stability properties of the jet. It is found that the presence of a finite-thickness shear layer can lead to an absolute instability for a range of density ratios, not seen when a simpler plug flow velocity profile is considered. It is also found that the inclusion of surface tension has a stabilizing effect on the convective instability but a destabilizing effect on the absolute instability. The stability results are used to obtain estimates for the breakup length of a planar liquid jet as the jet velocity varies. It is found that reducing the shear layer thickness within the jet causes the breakup length to decrease, while increasing the fluid velocity at the fluid interface within the shear layer causes the breakup length to increase. Combining these two effects into a profile, which evolves realistically with velocity, gives results in which the breakup length increases for small velocities and decreases for larger velocities. This behaviour agrees qualitatively with existing experiments on the breakup length of axisymmetric jets.

show abstract

Section: Introductionmentioning

confidence: 99%

Stability analysis and breakup length calculations for steady planar liquid jets

et al. 2010

View full text Add to dashboard Cite

show abstract

“…The Ohnesorge number is the ratio of the viscous capillary timescale to the capillary timescale. We describe the liquid jet by the one-dimensional model (Trouton 1906;Weber 1931;Eggers & Villermaux 2008)…”

Section: Base Flowmentioning

confidence: 99%

“…Capillary breakup occurs within a time τ which depends on the thread radius h, on the liquid density ρ, viscosity η and surface tension γ, and we know that most of this time is spent at developing an instability about the quasi-columnar shape of the thread, the subsequent phenomena occurring around the pinching instant at the drops separation being comparatively much faster (Eggers & Villermaux 2008). The time τ is either the capillary time ρh 3 /γ when inertia and surface tension are solely at play, or the viscous capillary time ηh/γ if viscous effects dominantly slow down the unstable dynamics.…”

Section: Introductionmentioning

confidence: 99%

“…The time τ is either the capillary time ρh 3 /γ when inertia and surface tension are solely at play, or the viscous capillary time ηh/γ if viscous effects dominantly slow down the unstable dynamics. When the jet issues from the nozzle ballistically, keeping its velocity and radius constant, the problem is indeed simple, and amounts to estimate correctly the relevant timescale τ to compute the so-called 'Liquid intact length' of the jet (see the corresponding section in Eggers & Villermaux (2008) for a complete discussion and experimental references, including the case when the jet suffers a shear instability with the surrounding environment). Subtleties arise when the axial velocity of the jet depends on axial distance z.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Capillary jet breakup by noise amplification

Dizès

Villermaux

2016

J. Fluid Mech.

View full text Add to dashboard Cite

A liquid jet falling by gravity ultimately destabilizes by capillary forces. Accelerating as it falls, the jet thins and stretches, causing the capillary instability to develop on a spatially varying substrate. We discuss quantitatively the interplay between instability growth, jet thinning and longitudinal stretching for two kinds of perturbations, either solely introduced at the jet nozzle exit, or affecting the jet all along its length. The analysis is conducted for any values of the liquid properties for sufficiently large flow rate. In all cases, we determine the net gain of the most dangerous perturbation for all downstream distances, thus predicting the jet length, the wavelength at breakup and the resulting droplet size.

show abstract

“…Surface tension affects the drop formation process, the breakup of jets [23] and the oscillations of the shapes of drops. Surface tension tends to keep the drops spherical in flight since spherical shapes minimize the surface energy [24].…”

Section: Fluid Dynamics Descriptionmentioning

confidence: 99%

Fluid dynamics topics in bloodstain pattern analysis: Comparative review and research opportunities

Attinger

Moore

Donaldson

et al. 2013

Forensic Science International

155

139

View full text Add to dashboard Cite

This comparative review highlights the relationships between the disciplines of bloodstain pattern analysis (BPA) in forensics and that of fluid dynamics (FD) in the physical sciences. In both the BPA and FD communities, scientists study the motion and phase change of a liquid in contact with air, or with other liquids or solids. Five aspects of BPA related to FD are discussed: the physical forces driving the motion of blood as a fluid; the generation of the drops; their flight in the air; their impact on solid or liquid surfaces; and the production of stains. For each of these topics, the relevant literature from the BPA community and from the FD community is reviewed. Comments are provided on opportunities for joint BPA and FD research, and on the development of novel FD-based tools and methods for BPA. Also, the use of dimensionless numbers is proposed to inform BPA analyses. Keywordsbloodstain pattern analysis, review, dimensionless number, drop generation, trajectory, impact, stain Disciplines Laboratory and Basic Science Research | Other Mechanical EngineeringComments NOTICE: this is the author's version of a work that was accepted for publication in Forensic Science International. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Forensic Science International, [231, 1-3, (2013) Abstract: This comparative review highlights the relationships between the disciplines of bloodstain pattern analysis (BPA) in forensics and that of fluid dynamics (FD) in the physical sciences. In both the BPA and FD communities, scientists study the motion and phase change of a liquid in contact with air, or with other liquids or solids. Five aspects of BPA related to FD are discussed: the physical forces driving the motion of blood as a fluid; the generation of the drops; their flight in the air; their impact on solid or liquid surfaces; and the production of stains. For each of these topics, the relevant literature from the BPA community and from the FD community is reviewed. Comments are provided on opportunities for joint BPA and FD research, and on the development of novel FD-based tools and methods for BPA. Also, the use of dimensionless numbers is proposed to inform BPA analyses.

show abstract

Physics of liquid jets

Cited by 1,552 publications

References 539 publications

Stability analysis and breakup length calculations for steady planar liquid jets

Stability analysis and breakup length calculations for steady planar liquid jets

Capillary jet breakup by noise amplification

Fluid dynamics topics in bloodstain pattern analysis: Comparative review and research opportunities

Contact Info

Product

Resources

About