WHY HOUR GLASSES TICK

Citation
X. Wu et al., WHY HOUR GLASSES TICK, Physical review letters, 71(9), 1993, pp. 1363-1366
Citations number
10
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
ISSN journal
0031-9007
Volume
71
Issue
9
Year of publication
1993
Pages
1363 - 1366
Database
ISI
SICI code
0031-9007(1993)71:9<1363:WHGT>2.0.ZU;2-R
Abstract
We have found experimentally that the flow of sand in an hour glass is oscillatory in a certain range of parameters. The oscillatory motion results from a coupling between the flow of sand and convection of air through the sand matrix. The period of the oscillation is remarkably insensitive to the grain size, while the mass of the sand contained in one period strongly depends on it.