Add a Media Piece
 
default edit
Back to the Gallery

This medium is available via another website:

Click here to view it.

Title: Faraday jets and sand

Description: When a 6-mm layer of fine sand with an average grain size of 40 ┬Ám is poured into a cylindrical container and shaken vertically, thin jets are seen to emerge from an airy cloud of grains, almost like protuberances from the corona of the sun.

A quasi two-dimensional setup reveals the jet-formation process: The sand accumulates in ripples, and below each of them air is entrained by the convective motion of the grains. Air bubbles form at the bottom and slowly rise through the sand. Every time a bubble reaches the surface, it creates a void, which thereupon collapses and focuses into a jet.

Credits: Marijn Sandtke, Devaraj van der Meer, Michel Versluis, and Detlef Lohse

References:

Web Page: http://pof.aip.org/pof/gallery/2003-sandtke.jsp#video

Contributed By: Tausif Billah

 
The eFluids editor for videos is G. M. "Bud" Homsy (bud@math.ubc.ca)
and for images is Jean Hertzberg (Hertzberg@colorado.edu).
Please contact them if you have any problems, questions, or concerns related to the galley or videos and images.
© Copyright on the videos is held by the contributors.
Apart from Fair Use, permission must be sought for any other purpose.