Bubble ring
A bubble ring, or ring bubble, is an underwater ring vortex where an air bubble occupies the core of the vortex, forming a ring shape. The ring of air as well as the nearby water spins poloidally as it travels through the water, much like a flexible bracelet might spin when it is rolled on to a person's arm. The faster the bubble ring spins, the more stable it becomes.[1] Bubble rings and smoke rings are both examples of vortex rings, the physics of which is still under active study in fluid dynamics.[2][3] Devices have been invented which generate bubble vortex rings.[4][5]
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[edit] Physics
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Dolphin play bubble rings Sea World |
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Extraordinary toroidal vortices YouTube |
Air bubbles in water having diameters greater than about two centimetres quickly become rings because water pressure increases with depth. Higher pressure water below the bubble overcomes the surface tension of the sphere, punching a hole in the centre to create a ring shape.[6]
[edit] Cetaceans
Cetaceans, such as beluga whales and dolphins, blow bubble rings. Dolphins sometimes engage in complex play behaviours, creating bubble rings on purpose, seemingly for amusement.[7] There are two main methods of bubble ring production: rapid puffing of a burst of air into the water and allowing it to rise to the surface, forming a ring; or swimming repeatedly in a circle and then stopping to inject air into the helical vortex currents thus formed. The dolphin will often then examine its creation visually and with sonar. They also appear to enjoy biting the vortex-rings they've created, so that they burst into many separate normal bubbles and then rise quickly to the surface.[8]
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A bubble ring forms a vortex ring, shaped like a doughnut which spins poloidally in the direction of the arrow
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A underwater diver blows a bubble ring
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Beluga whales blowing bubble rings
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Aerial view of a humpback bubble net
Humpback whales use another type of bubble ring when they forage for fish. They surround a school of forage fish with a circular bubble net and herd them into a bait ball.[9]
[edit] Human divers
Some scuba divers can create bubble rings by blowing air out of their mouth in a particular manner. Long bubble rings also can form spontaneously in turbulent water such as in heavy surf.
[edit] Other uses of the term
The term "bubble ring" is also used in other contexts. A common children's toy for blowing soap bubbles is called a bubble ring, and replaces the bubble pipe toy that was traditionally used for many years. Soapsuds are suspended on a ring connected by a stem to the screwcap of a bottle containing soapsuds.[10]
[edit] See also
[edit] Notes
- ^ Yoona SS and Heister SD (2004) "A nonlinear atomization model based on a boundary layer instability mechanism" Physics of Fluids, 16 (1): 47–61.
- ^ Ruban VP and Rasmussen JJ (2003) "Toroidal bubbles with circulation in ideal hydrodynamics: A variational approach" Phys. Rev, 68 (5).
- ^ Wang QX, Yeo KS, Khoo BC and Lam KY (2005) "Vortex ring modelling of toroidal bubbles" JournalTheoretical and Computational Fluid Dynamics, 19 (5): 1432-2250.
- ^ United States Patent: Simple method for the controlled production of vortex ring bubbles of a gas Issued patent: 6824125, 30 November 2004.
- ^ United States Patent: Simple, mechanism-free device, and method to produce vortex ring bubbles in liquids Patent number: 7300040. 27 November 2007.
- ^ Ken Marten; Karim Shariff; Suchi Psarakos; Don J. White. "Ring Bubbles of Dolphins". Scientific American. http://www.sciamdigital.com/index.cfm?fa=Products.ViewIssuePreview&ARTICLEID_CHAR=D0CD2470-180D-4C42-88B6-654E90AB55D..
- ^ "The physics of bubble rings and other diver's exhausts". http://www.deepocean.net/deepocean/index.php?science09.php. Retrieved 2006-10-24.
- ^ "Bubble rings: Videos and Stills". http://www.bubblerings.com/bubblerings/media.cfm. Retrieved 2006-10-24.
- ^ Acklin, Deb (2005-08-05). "Crittercam Reveals Secrets of the Marine World". National Geographic News. http://news.nationalgeographic.com/news/2002/06/0624_020624_TVbubble.html. Retrieved 2007-11-01.
- ^ Erhard G (2006) Designing with plastics Page 227. Hanser Verlag. ISBN 9781569903865
[edit] References
- Das1 D and Kumar V (2005) "Experimental Investigation of the Trajectory of Compressible Vortex Rings" 11th AIAA/CEAS Aeroacoustics Conference (26th AIAA Aeroacoustics Conference).
- Hameroff SR, Kaszniak AW and Scott A (1998) Toward a science of consciousness II: the second Tucson discussions and debates Page 558. MIT Press. ISBN 9780262082624.
- Lundgren TS and Mansour NN (1991) "Vortex ring bubbles" Journal of Fluid Mechanics, 224:177-196.
- Marten K, Shariff K, Psarakos S and White DJ (1996) “Ring bubbles of dolphins. A number of bottlenose dolphins in Hawaii can create shimmering, stable rings and helices of air as part of play” Scientific American, 275 (2): 82-87.
- McCowan B, Marino L, Vance E, Walke L and Reiss D (2000) "Bubble Ring Play of Bottlenose Dolphins (Tursiops truncatus): Implications for Cognition" Journal of Comparative Psychology, l14 (1):98-106.
[edit] External links
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Wikimedia Commons has media related to: Bubble rings |
- Dolphin bubble rings
- Dolphin bubble rings (video)
- Dolphin make and play bubble rings (video)
- Dolphin play bubble rings (video)
- Various videos of bubble rings
- BubbleRings.com Has some information on how bubble rings work.
