2014 Image Gallery

Image Descriptions 2014

Hydrodynamic Quantum Analogs

Daniel M. Harris, John W. M. Bush
Massachusetts Institute of Technology
Department of Mathematics
Cambridge, MA

Hydrodynamic Quantum AnalogFaraday waves form on the surface of a vibrated fluid bath when a critical vibration amplitude is exceeded (Figure 1) [1]. Below this threshold, a millimetric droplet can bounce indefinitely on the bath, exciting a localized field of Faraday waves. The bouncing drop may self-propel through a resonant interaction with its own wave field (Figure 2) and so translate steadily across the surface [2,3]. The walking drop system exhibits many features previously thought to be exclusive to the microscopic quantum realm, and represents a macroscopic realization of a pilot-wave system of the form proposed in the 1920s by Louis de Broglie [4].

Abstract

References
[1] M. Faraday, "On the forms and states of fluids on vibrating elastic surfaces", Philosophical Transactions of the Royal Society of London, vol.121, pp.319-340 (1831).

[2] S. Protière, A. Boudaoud & Y. Couder, "Particle-wave association on a fluid interface", Journal of Fluid Mechanics, vol.554, pp.85-108 (2006). http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=431290&fileId=S0022112006009190

[3] J. Moláček, J.W.M. Bush, "Drops walking on a vibrating bath: Towards a hydrodynamic pilot-wave theory" Journal of Fluid Mechanics, vol.727, pp.612-647 (2013). http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8947531&fileId=S0022112013002802

[4] J.W.M. Bush, "Pilot-wave hydrodynamics", Annual Review of Fluid Mechanics, vol.47, pp. 269-292 (2015). http://www.annualreviews.org/doi/pdf/10.1146/annurev-fluid-010814-014506

Usage Information
This image may be freely reproduced with the accompanying credit: D.M.Harris and J.W.M.Bush

Contact Information
John W. M. Bush
Massachusetts Institute of Technology
Department of Mathematics
Cambridge, MA

Unexpected Trapping of Particles

Steven Wang, Robert Stewart, Guy Metcalfe
CSIRO
Australia

Unexpected Trapping of ParticlesEncountered throughout nature and industry are fluid flows containing particles, and understanding or manipulating the ultimate arrangement of particles in the flow is a paramount goal. Here we expose a mechanism for particle localization that arises from interaction of the intrinsic inertia of particle and fluid by visualizing the motion of particles in laminar stirred tank flow. The tank and impeller systems have been in consistent use over a number of centuries, but this particle-localization phenomenon has never been reported.

Usage Information
To use this image, please contact: Steven Wang

Webbed Jet

B. NÉEL, H. LHUISSIER, L. LIMAT
MSC, Université Paris Diderot & CNRS
France

Webbed JetBottom view of a high velocity viscoelastic jet impacting on a plate. On impact, the elastic stresses in the liquid destabilize the jet interface. This spontaneous symmetry-breaking forms a webbed jet which has (here) respectively 13 and 5 wings.

Abstract

References
H. LHUISSIER, B. NÉEL & L. LIMAT , "Viscoelasticity breaks the symmetry of impacting jets" Phys. Rev. Lett., in press.

Usage Information
This image may be used for educational purposes only. Please credit: B. NÉEL & H. LHUISSIER / MSC & CNRS

Contact Information
Henri Lhuissier
MSC - Université Paris Diderot, CNRS
10 rue Alice Domon et Léonie Duquet
75025 Paris Cedex 13, France

Spray Formation of a Gel Using Impinging Jets

Neil S. Rodrigues, Jian Gao, Jun Chen, Paul E. Sojka
M.J. Zucrow Laboratories
School of Mechanical Engineering
Purdue University

Spray Formation of a Gel Using Impinging JetsTwo regimes of impinging jet spray formation using 1.0 wt.-% kappa carrageenan, a water-based gelled propellant simulant, are presented in the images. This image shows the spray pattern at jet Herschel-Bulkley Extended (HBE) generalized Reynolds number Rej,HBE = 1.75E+03. At the lower jet HBE Reynolds number, the influence of the viscous force leads to formation of a distinct sheet and long noodle-like ligaments. At the higher jet HBE Reynolds number, the inertial force dominates, causing the sheet to break up a short distance from the impingement point and the dense formation of short vermicelli-like ligaments. A few large drops are formed from the ligaments at the lower jet HBE Reynolds number, whereas a large number of small drops are formed at the higher jet HBE Reynolds number.

Usage Information
Reporters may freely use these images. Credit: N.S. Rodrigues, J. Gao, J. Chen, P.E. Sojka (2014)

Contact Information
Neil S. Rodrigues
M.J. Zucrow Laboratories
School of Mechanical Engineering
Purdue University

Unexpected Trapping of Particles 2

Steven Wang, Robert Stewart, Guy Metcalfe
CSIRO
Australia

Unexpected Trapping of Particles 2Encountered throughout nature and industry are fluid flows containing particles, and understanding or manipulating the ultimate arrangement of particles in the flow is a paramount goal. Here we expose a mechanism for particle localization that arises from interaction of the intrinsic inertia of particle and fluid by visualizing the motion of particles in laminar stirred tank flow. The tank and impeller systems have been in consistent use over a number of centuries, but this particle-localization phenomenon has never been reported.

Usage Information
To use this image, please contact: Steven Wang

Flow Pattern From a Jet Impingement

Hamid Ait Abderrahmane
Thuwal, Saudi Arabia

Aslan Kasimov
King Abdullah University of Science and Technology,
Thuwal, Saudi Arabia

Flow Pattern From a Jet ImpingementWhen a fluid jet falls vertically at high Reynolds number and strikes a horizontal plate, a circular poloidal flow (roller) may arise as a result of instability of the circular hydraulic jump. Observing from below the plate, we show the symmetry breaking and the associated self-organized structures that follow the destabilization of the circular roller by the injection of air, with a syringe, at the entrance of the flow. The inner perimeter of the roller becomes of polygonal shape, strong jets flow from the corners of the polygon, wake vortices form in each side of the jets. In the space between the jets there is a region where the fluid flows back toward the interior because it has smaller velocity than the escape velocity from the central region.

Usage Information
To use this image, please contact: Hamid Ait Abderrahmane

Hydrodynamic Quantum Analogs 2

Daniel M. Harris, John W. M. Bush
Massachusetts Institute of Technology
Department of Mathematics
Cambridge, MA

Hydrodynamic Quantum Analogs 2Faraday waves form on the surface of a vibrated fluid bath when a critical vibration amplitude is exceeded (Figure 1) [1]. Below this threshold, a millimetric droplet can bounce indefinitely on the bath, exciting a localized field of Faraday waves. The bouncing drop may self-propel through a resonant interaction with its own wave field (Figure 2) and so translate steadily across the surface [2,3]. The walking drop system exhibits many features previously thought to be exclusive to the microscopic quantum realm, and represents a macroscopic realization of a pilot-wave system of the form proposed in the 1920s by Louis de Broglie [4].

Abstract

References
[1] M. Faraday, "On the forms and states of fluids on vibrating elastic surfaces", Philosophical Transactions of the Royal Society of London, vol.121, pp.319-340 (1831).

[2] S. Protière, A. Boudaoud & Y. Couder, "Particle-wave association on a fluid interface", Journal of Fluid Mechanics, vol.554, pp.85-108 (2006). http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=431290&fileId=S0022112006009190

[3] J. Moláček, J.W.M. Bush, "Drops walking on a vibrating bath: Towards a hydrodynamic pilot-wave theory" Journal of Fluid Mechanics, vol.727, pp.612-647 (2013). http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8947531&fileId=S0022112013002802

[4] J.W.M. Bush, "Pilot-wave hydrodynamics", Annual Review of Fluid Mechanics, vol.47, pp. 269-292 (2015). http://www.annualreviews.org/doi/pdf/10.1146/annurev-fluid-010814-014506

Usage Information
This image may be freely reproduced with the accompanying credit: D.M.Harris and J.W.M.Bush

Contact Information
John W. M. Bush
Massachusetts Institute of Technology
Department of Mathematics
Cambridge, MA

Webbed Jet 2

B. NÉEL, H. LHUISSIER, L. LIMAT
MSC, Université Paris Diderot & CNRS
France

Webbed Jet 2Side view of a high velocity viscoelastic jet impacting on a plate. On impact, the elastic stresses in the liquid destabilize the jet interface. This spontaneous symmetry-breaking forms a webbed jet which has (here) respectively 13 and 5 wings.

Abstract

References
H. LHUISSIER, B. NÉEL & L. LIMAT, "Viscoelasticity breaks the symmetry of impacting jets" Phys. Rev. Lett., in press.

Usage Information
This image may be used for educational purposes only. Please credit: B. NÉEL & H. LHUISSIER / MSC & CNRS

Contact Information
Henri Lhuissier
MSC - Université Paris Diderot, CNRS
10 rue Alice Domon et Léonie Duquet
75025 Paris Cedex 13, France

Unexpected Trapping of Particles 3

Steven Wang, Robert Stewart, Guy Metcalfe
CSIRO
Australia

Unexpected Trapping of Particles 3Encountered throughout nature and industry are fluid flows containing particles, and understanding or manipulating the ultimate arrangement of particles in the flow is a paramount goal. Here we expose a mechanism for particle localization that arises from interaction of the intrinsic inertia of particle and fluid by visualizing the motion of particles in laminar stirred tank flow. The tank and impeller systems have been in consistent use over a number of centuries, but this particle-localization phenomenon has never been reported.

Usage Information
To use this image, please contact: Steven Wang

Spray Formation of a Gel Using Impinging Jets 2

Neil S. Rodrigues, Jian Gao, Jun Chen, Paul E. Sojka
M.J. Zucrow Laboratories
School of Mechanical Engineering
Purdue University

Spray Formation of a Gel Using Impinging Jets 2Two regimes of impinging jet spray formation using 1.0 wt.-% kappa carrageenan, a water-based gelled propellant simulant, are presented in the images. This image shows the spray pattern at Rej,HBE = 6.73E+04. At the lower jet HBE Reynolds number, the influence of the viscous force leads to formation of a distinct sheet and long noodle-like ligaments. At the higher jet HBE Reynolds number, the inertial force dominates, causing the sheet to break up a short distance from the impingement point and the dense formation of short vermicelli-like ligaments. A few large drops are formed from the ligaments at the lower jet HBE Reynolds number, whereas a large number of small drops are formed at the higher jet HBE Reynolds number.

Usage Information
Reporters may freely use these images. Credit: N.S. Rodrigues, J. Gao, J. Chen, P.E. Sojka (2014)

Contact Information
Neil S. Rodrigues
M.J. Zucrow Laboratories
School of Mechanical Engineering
Purdue University

Do you want to entertain your kids during breakfast on Sunday?

Jakub Nowakowski, Maria L. Ekiel-Jezewska
Institute of Fundamental Technological Research
Polish Academy of Sciences
Pawinskiego 5B, 02-106 Warsaw, Poland

Jar of liquid honey and a number of small identical spherical beadsTake a very high jar of liquid honey and a number of small identical spherical beads, e.g. millimeter steel balls from a ball bearing. Prepare the beads before starting: mix them with a small amount of honey. Next, take into your fingers a triplet of the beads `glued' by the sticky liquid. Try to keep them as close to each other as possible and in a vertical plane, put above the open jar and then release and let them fall into honey. Guess what will you see? Hint: View the Image ‘Dancing beads, which try to oscillate periodically while falling in a viscous fluid’

Usage Information
This image may be freely reproduced with the accompanying credit: M.L. Ekiel-Jezewska/IPPT PAN

Contact Information
Maria L. Ekiel-Jezewska
Institute of Fundamental Technological Research
Polish Academy of Sciences
Pawinskiego 5B, 02-106 Warsaw, Poland
+48 826 12 81 ext. 227

Dancing beads, which try to oscillate periodically while falling in a viscous fluid

Jakub Nowakowski, Maria L. Ekiel-Jezewska
Institute of Fundamental Technological Research
Polish Academy of Sciences
Pawinskiego 5B, 02-106 Warsaw, Poland

evolution of beadsIn observations (top), experiments (middle) and theory (bottom), a similar evolution of the beads’ relative positions takes place. The configurations at time T/6 are almost the mirror images of the ones at time equal zero (the mirror is vertical), except a permutation of particles. Therefore, periodic motions with the period T exist. In experiments, they are unstable and usually break up after a bit longer than 1/6 of the period.

Top and middle panels by M. L. Ekiel-Jezewska and Jakub Nowakowski. Bottom panel reproduced with permission from M. L. Ekiel-Jezewska, T. Gubiec, P. Szymczak, Stokesian dynamics of close particles, Phys. Fluids, 20, 063102 (2008). Copyright 2008. AIP Publishing LLC.

Usage Information
To use this Image, please contact: Maria L. Ekiel-Jezewska

Contact Information
Maria L. Ekiel-Jezewska
Institute of Fundamental Technological Research
Polish Academy of Sciences
Pawinskiego 5B, 02-106 Warsaw, Poland
+48 826 12 81 ext. 227

The Lions of the Piazza del Popolo

Emmanuel Villermaux
Aix-Marseille University, IRPHE
Marseille, France

The lions of the piazza del popoloRome, Piazza del Popolo, the lions of the central fountain expectorate a turbulent water sheet. Random velocity fluctuations in the liquid nucleate holes which, driven by surface tension, grow and merge, leaving the sheet as a set of connected ligaments. These corrugated ligament further breakup into a collection of disjointed droplets broadly distributed in size.

Usage Information
To use this image, please contact: E. Villermaux

Contact Information
Emmanuel Villermaux
Affiliation: Aix-Marseille University, IRPHE
Location: Marseille

Cavitation bubbles and Tethered Particles

Prof. Sunghwan (Sunny) Jung
Virginia Tech
Blacksburg, VA

Cavitation bubbles and tethered particlesThe image shows a cavitation bubble (on the right) as it induces the motion of a glass particle (on the left) tethered to a wire in water.

This cavitation bubble is caused by a 50-Volt spark at t=0 ms. In turn, this spark nucleates a bubble in water, creating fluid flows around it. As the cavitation bubble expands through t=0.33 ms, the fluidflows radially outward from the cavitation thereby pushing the glass particle away. The bubble reaches its maximum size at t=0.67 ms and starts to decrease its volume. At this shrinking stage, the bubble is no longer able to maintain its spherical shape as in t=0.99 ms, and will collapse in on itself next to the particle, ³sucking² the surrounding fluid inward.

We plan to investigate the effect of particle size, density, distance from the cavitation bubble to understand the dynamics of the particle-bubble interaction.

Usage Information
This image may be freely reproduced with the accompanying credit: S. Jung/Virginia Tech

Contact Information
Prof. Sunghwan (Sunny) Jung
Department of Biomedical Engineering and Mechanics
Affiliate Professor of Mechanical Engineering and Physics
228 Norris Hall, Virginia Tech, Blacksburg, VA
Website: www.esm.vt.edu/~sunnyjsh/

Mushroom-like vortices are not all the same/ Freely travelling vortex rings in various fluids

Julie Albagnac, David Laupsien, Dominique Anne-Archard
Institut de Mécanique des Fluides de Toulouse
Toulouse, FRANCE

Are vortex rings always the same (from a topological and/or dynamical point of view)? no!

14-archard2014-thumb.jpgIt is now well known that both topology and dynamics of such a vortical structure strongly depend on the generation conditions. The present study focuses on the effect of the fluid nature itself. Indeed, despite the same generation conditions (same piston-cylinder apparatus + same stroke ratio ending to the same relative position to the cylinder exit) and the same inertial effect (same generalized Reynolds number), Figures 1 and 2 highlight the strong influence of the fluid nature on annular vortex behavior. Figure 1 shows obvious different topologies for Newtonian (left) and viscoelastic (right) vortex rings. Figure 2 presents a time evolution of a vortex ring in a Newtonian (top) and viscoelastic (bottom) fluid. Newtonian vortex ring furls, propagates by auto-induced effect and diffuses (increase of its diameter) while propagating. Non-Newtonian viscoelastic vortex ring, instead, first furls and expends as it is propagating away then stops, unfurls and goes back, contracting in the radial direction.

Abstract

Usage Information
These images may be freely reproduced with the accompanying credit: "Image by J. Albagnac, D. Laupsien and D. Anne-Archard, IMFT, France"

Contact Information
Julie Albagnac
Institut de Mécanique des Fluides de Toulouse
Toulouse, FRANCE

Vortex structure of a flapping flapping wing

Oscar Curet, Cyndee Finkel, Karl von Ellenrieder
Florida Atlantic University
Boca Raton, Florida

Daniel Bissell
TSI

Particle Image Velocimetry

Flow structure behind a flapping wing at the end of the downstroke captured by volumetric Particle Image Velocimetry. The streamlines, shown with solid lines, are colored by the magnitude of the velocity. The translucent gray surfaces show isosurface of the vorticity. For the experiments, Re = 7500 and St = 0.35.

3D flow structure

3D flow structure behind a flapping wing captured by volumetric Particle Image Velocimetry. The wing generates a strong downward jet at the end of the downstroke associated with a vortex ring. This is illustrated by the streamlines shown with solid lines and are colored by the magnitude of the velocity. The translucent gray surfaces show isosurface of the vorticity. For the experiments, Re = 7500 and St = 0.35.

Usage Information
To use this image, please contact: Oscar Curet 

Contact Information
Oscar Curet
Florida Atlantic University
Department of Ocean and Mechanical Engineering
561-297-1560

Virtual Pressroom Archive

Virtual press rooms feature stories and images related to the Division's annual meetings and other news related to fluid dynamics.

APS DFD Annual Meeting Archives

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Image & Video Galleries

Every year, the APS Division of Fluid Dynamics hosts posters and videos that show stunning images, graphics, and videos from either computational or experimental studies of flow phenomena. A panel of referees selects the most outstanding entries based on artistic content, originality, and their ability to convey information. The 67th Annual Meeting Image Gallery archives a subset of these images and videos on the APS DFD website.