Relaxation processes in hourglasses

The flow of sand through an hourglass, or a capillary, shows an interresting behaviour.

Here is a film sequence of the flow of 5 different types of sand.

100 microns glass

180 microns glass

220 microns glass

400 microns rough glass

Booming dune sand

Below is a photo of the experiment where we studied the flow of sand.

Collaborators :

Peter Dimon, Christian Veje

Papers :

C. T. Veje and P. Dimon,
Power spectra of flow in an hourglass,
Phys. Rev. E, 56 4376 (1997) [gzipped ps (300 k)]