Virvel
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Virvel, latin vortex, är i strömningsmekanik en rotationsrörelse i en fluid. Virvlar kan utgöras av en så kallad fri virvel där enskild virvel underhålls energimässigt av en strömningskälla eller en sänka i virvelns centrum som då bildar en logaritmisk strömningsform.
Ett kaotiskt system av virvlar kallas turbulens.
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Wikimedia Commons har media som rör Virvel.
Media som används på denna webbplats
Question book-4.svg
Författare/Upphovsman: Tkgd2007, Licens: CC BY-SA 3.0
A new incarnation of Image:Question_book-3.svg, which was uploaded by user AzaToth. This file is available on the English version of Wikipedia under the filename en:Image:Question book-new.svg
Författare/Upphovsman: Tkgd2007, Licens: CC BY-SA 3.0
A new incarnation of Image:Question_book-3.svg, which was uploaded by user AzaToth. This file is available on the English version of Wikipedia under the filename en:Image:Question book-new.svg
Low pressure system over Iceland.jpg
A beautifully-formed low-pressure system swirls off the southwestern coast of Iceland, illustrating the maxim that "nature abhors a vacuum." The vacuum in this case would be a region of low atmospheric pressure. In order to fill this void, air from a nearby high-pressure system moves in, in this case bringing clouds along for the ride. And because this low-pressure system occurred in the Northern Hemisphere, the winds spun in toward the center of the low-pressure system in a counter-clockwise direction; a phenomenon known as the Coriolis force (in the Southern Hemisphere, the Coriolis force would be manifested in a clockwise direction of movement). The clouds in the image resembled pulled cotton and lace as they spun in a lazy hurricane-like pattern. This huge system swirled over the Denmark Strait in between Greenland and Iceland. The image was taken by the Aqua MODIS instrument on September 4, 2003.
A beautifully-formed low-pressure system swirls off the southwestern coast of Iceland, illustrating the maxim that "nature abhors a vacuum." The vacuum in this case would be a region of low atmospheric pressure. In order to fill this void, air from a nearby high-pressure system moves in, in this case bringing clouds along for the ride. And because this low-pressure system occurred in the Northern Hemisphere, the winds spun in toward the center of the low-pressure system in a counter-clockwise direction; a phenomenon known as the Coriolis force (in the Southern Hemisphere, the Coriolis force would be manifested in a clockwise direction of movement). The clouds in the image resembled pulled cotton and lace as they spun in a lazy hurricane-like pattern. This huge system swirled over the Denmark Strait in between Greenland and Iceland. The image was taken by the Aqua MODIS instrument on September 4, 2003.