Open problems in active chaotic flows: Competition between chaos and order in granular materials
DSpace at IIT Bombay
View Archive InfoField | Value | |
Title |
Open problems in active chaotic flows: Competition between chaos and order in granular materials
|
|
Creator |
OTTINO, JM
KHAKHAR, DV |
|
Subject |
axial segregation
rotating cylinders mixtures particles solids organization aggregation dynamics symmetry liquids |
|
Description |
There are many systems where interaction among the elementary building blocks-no matter how well understood-does not even give a glimpse of the behavior of the global system itself. Characteristic for these systems is the ability to display structure without any external organizing principle being applied. They self-organize as a consequence of synthesis and collective phenomena and the behavior cannot be understood in terms of the systems' constitutive elements alone. A simple example is flowing granular materials, i.e., systems composed of particles or grains. How the grains interact with each other is reasonably well understood; as to how particles move, the governing law is Newton's second law. There are no surprises at this level. However, when the particles are many and the material is vibrated or tumbled, surprising behavior emerges. Systems self-organize in complex patterns that cannot be deduced from the behavior of the particles alone. Self-organization is often the result of competing effects; flowing granular matter displays both mixing and segregation. Small differences in either size or density lead to flow-induced segregation and order; similar to fluids, noncohesive granular materials can display chaotic mixing and disorder. Competition gives rise to a wealth of experimental outcomes. Equilibrium structures, obtained experimentally in quasi-two-dimensional systems, display organization in the presence of disorder, and are captured by a continuum flow model incorporating collisional diffusion and density-driven segregation. Several open issues remain to be addressed. These include analysis of segregating chaotic systems from a dynamical systems viewpoint, and understanding three-dimensional systems and wet granular systems (slurries). General aspects of the competition between chaos-enhanced mixing and properties-induced de-mixing go beyond granular materials and may offer a paradigm for other kinds of physical systems. (C) 2002
|
|
Publisher |
AMER INST PHYSICS
|
|
Date |
2011-07-16T10:44:15Z
2011-12-26T12:49:44Z 2011-12-27T05:35:21Z 2011-07-16T10:44:15Z 2011-12-26T12:49:44Z 2011-12-27T05:35:21Z 2002 |
|
Type |
Article
|
|
Identifier |
CHAOS, 12(2), 400-407
1054-1500 http://dx.doi.org/10.1063/1.1468247 http://dspace.library.iitb.ac.in/xmlui/handle/10054/4408 http://hdl.handle.net/10054/4408 |
|
Language |
en
|
|