Spontaneous chaotic granular mixing

Troy Shinbrot, Albert Alexander and Fernando J. Muzzio ()
Additional contact information
Troy Shinbrot: Pharmaceutical Engineering Program, Rutgers University
Albert Alexander: Pharmaceutical Engineering Program, Rutgers University
Fernando J. Muzzio: Pharmaceutical Engineering Program, Rutgers University

Nature, 1999, vol. 397, issue 6721, 675-678

Abstract: Abstract There are several types of instabilities in fluid mechanics that lead to spontaneous chaotic mixing and intricate patterns. Classical examples include the Kelvin–Helmholtz instability1,2 in shear layers, the instability of Taylor–Couette flow between rotating cylinders3,4 and the Rayleigh-Bénard instability in thermal convection5. More recently, a variety of two- and three-dimensional chaotic mixing phenomena have been observed in other geometries6,7,8,9. Mixing in granular flows10,11, unlike that in stirred fluids, is thought to be diffusive—although periodic forcing has been used to enhance granular mixing12,13, spontaneous chaotic granular mixing has not previously been reported. Here we report the observation of chaotic granular mixing patterns in simple cylindrical tumblers partially filled with fine grains. The patterns form spontaneously when sufficiently fine grains (≲300 µm diameter) are blended. We identify the mechanism by which the chaotic patterns are produced: a periodic stick–slip behaviour occurs in the shear layer separating static and flowing regions of grains. This causes weakly cohesive grains to mix at rates overwhelmingly exceeding those achievable for previously studied11,14 freely flowing grains.

Date: 1999
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.nature.com/articles/17760 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:397:y:1999:i:6721:d:10.1038_17760

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/17760

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().