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Open problems in active chaotic flows: Competition between chaos and order in granular materials

DSpace at IIT Bombay

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Field 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