Review of chaos in the dynamics and rheology of suspensions of orientable particles in simple shear ow subject to an external periodic force
IR@C-MMACS: CSIR-Centre for Mathematical Modelling and Computer Simulation, Bangalore
View Archive InfoField | Value | |
Title |
Review of chaos in the dynamics and rheology
of suspensions of orientable particles in simple
shear
ow subject to an external periodic
force
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Creator |
T R, Ramamohan
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Subject |
Computational Fluid dynamics
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Description |
We review results obtained over a period of about a decade on a class of technologically
and fundamentally important problems in suspension rheology viz., the
dynamics and rheology of dipolar suspensions of orientable particles in simple shear
ow. We also attempt to put our results into context with respect to recent work
Preprint submitted to Journal of Non-Newtonian Fluid mechanics3 September 2004
on rheochaos. The areas explored in this review include e�ects such as the
uid
ow �eld, external forcing, Brownian di�usion, hydrodynamic interactions and their
impact on the rheological properties of the suspension. The main feature of the presentation
is the use of a uniform framework in which one or more of the above
e�ects can be studied, based on Langevin type equations for particle orientations
combined with a brute-force technique for computing orientational averages. These
models are capable of capturing dynamical behaviour in the system such as the
presence of subharmonics or chaos, both in the dynamics and rheology, which current
models based on Fokker-Planck type equations cannot. The tools developed
allow for investigating how chaos in the system is a�ected by Brownian di�usion
and hydrodynamic interactions. The presence of chaos opens up a number of novel
possibilities for dynamical and rheological behaviour of the system, which can be
put to effcient use in many ways, eg. in separating particles by aspect ratio and in
developing computer controlled intelligent rheology. The results also have implications
for certain areas of chaos theory, such as a new intermittency route to chaos
and the possibility of non-trivial collective behaviour in spatially extended systems.
These studies highlight certain deficiencies in current techniques in the literature
for handling the rheology of dilute and semi-dilute suspensions. In the presence of
Brownian motion the proposed method computes the averages by simulating a set
of deterministic equations rather than stochastic equations, leading to signi�ficant
improvements in computational efficiency. This technique can be used to compute
the orientation averages in certain parameter regimes where usual methods render
the problem difficult to handle. The systems considered may also serve as a
paradigm for analysing how microscopic chaotic
fluctuations in spatially extended
systems a�ffect macroscopic averages.
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Publisher |
CSIR Centre for Mathematical Modelling and Computer Simulation
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Date |
2004-09-03
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Type |
Monograph
NonPeerReviewed |
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Format |
application/pdf
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Identifier |
http://cir.cmmacs.ernet.in/197/1/rrcm0405abs.pdf
T R, Ramamohan (2004) Review of chaos in the dynamics and rheology of suspensions of orientable particles in simple shear ow subject to an external periodic force. Technical Report. CSIR Centre for Mathematical Modelling and Computer Simulation, C-MMACS,Bangalore 560037,India. (Unpublished) |
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Relation |
http://cir.cmmacs.ernet.in/197/
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