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The Marangoni effect: A fluid phenom (w/ Video)


What do a wine glass on Earth and an International Space Station experiment have in common? Well, observing the wine glass would be one of few ways to see and understand the experiment being performed in space.


Ever heard someone say their wine has "legs" or "tears of wine?"


Wine legs or tears of wine is a phenomenon manifested as a ring of clear liquid that forms near the top of a glass above the surface of wine. The drops continuously form and fall in rivulets back into the liquid. One factor in the way fluid moves is called Marangoni convection, or flow, and Japan Aerospace Exploration Agency researchers are very interested in studying it in a gravity-free environment.


Marangoni convection is the tendency for heat and mass to travel to areas of higher surface tension within a liquid. Surface tension is a property of a liquid that causes the surface portion of liquid to be attracted to another surface, such as a drop of mercury that forms a cohesive ball in a thermometer or droplets of water on a well-waxed car. This phenomenon is named after Italian physicist Carlo Marangoni who first studied the phenomenon in the 19th century.


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Lees verder: http://www.physorg.com/news/2011-03-marang...enom-video.html


Bron: Physorg