At the edge of a 14-cm-diameter round sheet of viscous liquid, the liquid is ejected as long threads that then fragment into drops. Villermaux, Pistre & Lhuissier, Journ. of Fluid Mech., 2013, Vol 730, pp 607-625 ©Cambridge Univ Press
At the edge of a 14-cm-diameter round sheet of viscous liquid, the liquid is ejected as long threads that then fragment into drops.
A water drop immersed in a pool of sunflower oil at 190°C becomes superheated and boils in an explosive fashion (sequence goes from left to right, top to bottom). The drop vaporizes and forms a large bubble of water vapor that oscillates and fragments into smaller bubbles. M. VAN LIMBEEK, et. al., Physics of Fluids 25, 091102 (2013). ©AIP Publishing LLC.
A water drop immersed in a pool of sunflower oil at 190°C becomes superheated and boils in an explosive fashion (sequence goes from left to right, top to bottom). The drop vaporizes and forms a large bubble of water vapor that oscillates and fragments into smaller bubbles.
A bursting bubble with a radius of 9 mm. Courtesy of H. Lhuissier and E. Villermaux
A bursting bubble with a radius of 9 mm.
A jet of water streaming against a solid object can also create a bell-shaped surface. Here, air pressure inside the bell deflects the liquid, causing the bell to collapse. H. Lhuissier & E. Villermaux, Journal of Fluid Mech., 2012, Vol 693, pp 508-540 ©Cambridge Univ. Press
A jet of water streaming against a solid object can also create a bell-shaped surface. Here, air pressure inside the bell deflects the liquid, causing the bell to collapse.
A below-surface view of a water drop falling into a pool of silicone oil. Each row shows the drop falling at a different speed, increasing from top to bottom. The drop forms a crater in the oil, which appears as a dark shape, before continuing downward. H. Lhuissier, C. Sun, A. Prosperetti, & D. Lohse, Phys. Rev. Lett. 110, 264503-(5) 2013. © APS
A below-surface view of a water drop falling into a pool of silicone oil. Each row shows the drop falling at a different speed, increasing from top to bottom. The drop forms a crater in the oil, which appears as a dark shape, before continuing downward.
A thin sheet of water, which is created by shooting a jet on a small solid surface, flaps around like a flag in the wind. H. Lhuissier & E. Villermaux, Journal of Fluid Mech, 2012, Vol 693, pp 508-540 © Cambridge Univ Press
A thin sheet of water, which is created by shooting a jet on a small solid surface, flaps around like a flag in the wind.
When a jet of viscoelastic fluid—liquids such as gels and pastes—hits a wall, it forms five wings that protrude outward. H. Lhuissier, B. Néel, & L. Limat, Phys. Rev. Lett. 113, 194502-(5) 2014. Copyright (2014) by APS.
When a jet of viscoelastic fluid—liquids such as gels and pastes—hits a wall, it forms five wings that protrude outward.
An edge-on view of a soap film that’s punctured on the left side. As the film recedes toward the right in this time-lapse series, it flaps in the air like a flag. H. Lhuissier and E. Villermaux, Phys. Rev. Lett. 103, 054501-(4) 2009. Copyright (2014) by APS
An edge-on view of a soap film that’s punctured on the left side. As the film recedes toward the right in this time-lapse series, it flaps in the air like a flag.
When you shoot a jet of water against a small disk, the liquid streams outward, forming a radial sheet. This sequence shows water being ejected from the edge of such a sheet in the form of jets and drops. Gordillo, Lhuissier & Villermaux, Jour. of Fluid Mech., 2014, Vol 754, pp R1-R11 ©Cambridge Univ. Press
When you shoot a jet of water against a small disk, the liquid streams outward, forming a radial sheet. This sequence shows water being ejected from the edge of such a sheet in the form of jets and drops.
Holes in a sheet of water grow and merge. When the rims of those holes join, they form filaments that break up into droplets. M. VAN LIMBEEK, et. al., Physics of Fluids 25, 091102 (2013). ©AIP Publishing LLC.
Holes in a sheet of water grow and merge. When the rims of those holes join, they form filaments that break up into droplets.
Liquids come in many forms, from bubbles and droplets to jets and sheets. Henri Lhuissier of Paris Diderot University and his colleagues use high-speed cameras to zoom in on the physics behind all kinds of liquid phenomena, which arise throughout nature, such as in the formation of raindrops and morning dew, and the dissemination of some fungal and bacterial spores. Knowing how small bubbles pop, for example, is important for learning how sea foam on top of breaking waves releases sea spray into the atmosphere. The tiny particles from sea spray make up a good portion of the atmosphere’s aerosols, which influence the climate and help induce rain.
Understanding liquids and their various forms and behaviors is useful in industry, too. For example, this kind of liquid physics is important for inkjet printing, the mechanisms that scatter fuel into tiny droplets inside engines, coating glass, using liquid jets to cut and clean, and developing microfluidic devices used in biology, chemistry, and medicine.
And, of course, these experiments make for some beautiful pictures.
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