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Laminar dispersion at high Péclet numbers in finite-length channels : Effects of the near-wall velocity profile and connection with the generalized Leveque problem

Giona, M.; Adrover, A.; Cerbelli, S. and Garofalo, F. LU (2009) In Physics of Fluids 21(12). p.1-20
Abstract

This article develops the theory of laminar dispersion in finite-length channel flows at high Péclet numbers, completing the classical Taylor-Aris theory which applies for long-term, long-distance properties. It is shown, by means of scaling analysis and invariant reformulation of the moment equations, that solute dispersion in finite length channels is characterized by the occurrence of a new regime, referred to as the convection-dominated transport. In this regime, the properties of the dispersion boundary layer and the values of the scaling exponents controlling the dependence of the moment hierarchy on the Péclet number are determined by the local near-wall behavior of the axial velocity. Specifically, different scaling laws in the... (More)

This article develops the theory of laminar dispersion in finite-length channel flows at high Péclet numbers, completing the classical Taylor-Aris theory which applies for long-term, long-distance properties. It is shown, by means of scaling analysis and invariant reformulation of the moment equations, that solute dispersion in finite length channels is characterized by the occurrence of a new regime, referred to as the convection-dominated transport. In this regime, the properties of the dispersion boundary layer and the values of the scaling exponents controlling the dependence of the moment hierarchy on the Péclet number are determined by the local near-wall behavior of the axial velocity. Specifically, different scaling laws in the behavior of the moment hierarchy occur, depending whether the cross-sectional boundary is smooth or nonsmooth (e.g., presenting corner points or cusps). This phenomenon marks the difference between the dispersion boundary layer and the thermal boundary layer in the classical Leveque problem. Analytical and numerical results are presented for typical channel cross sections in the Stokes regime. © 2009 American Institute of Physics.

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author
publishing date
type
Contribution to journal
publication status
published
subject
in
Physics of Fluids
volume
21
issue
12
pages
20 pages
publisher
American Institute of Physics
external identifiers
  • Scopus:76249096777
ISSN
1070-6631
DOI
10.1063/1.3263704
language
English
LU publication?
no
id
f79b35cf-119c-4465-883c-7bb6a7402ea0
date added to LUP
2016-06-27 10:09:09
date last changed
2016-07-15 14:10:21
@misc{f79b35cf-119c-4465-883c-7bb6a7402ea0,
  abstract     = {<p>This article develops the theory of laminar dispersion in finite-length channel flows at high Péclet numbers, completing the classical Taylor-Aris theory which applies for long-term, long-distance properties. It is shown, by means of scaling analysis and invariant reformulation of the moment equations, that solute dispersion in finite length channels is characterized by the occurrence of a new regime, referred to as the convection-dominated transport. In this regime, the properties of the dispersion boundary layer and the values of the scaling exponents controlling the dependence of the moment hierarchy on the Péclet number are determined by the local near-wall behavior of the axial velocity. Specifically, different scaling laws in the behavior of the moment hierarchy occur, depending whether the cross-sectional boundary is smooth or nonsmooth (e.g., presenting corner points or cusps). This phenomenon marks the difference between the dispersion boundary layer and the thermal boundary layer in the classical Leveque problem. Analytical and numerical results are presented for typical channel cross sections in the Stokes regime. © 2009 American Institute of Physics.</p>},
  author       = {Giona, M. and Adrover, A. and Cerbelli, S. and Garofalo, F.},
  issn         = {1070-6631},
  language     = {eng},
  number       = {12},
  pages        = {1--20},
  publisher    = {ARRAY(0x7d23580)},
  series       = {Physics of Fluids},
  title        = {Laminar dispersion at high Péclet numbers in finite-length channels : Effects of the near-wall velocity profile and connection with the generalized Leveque problem},
  url          = {http://dx.doi.org/10.1063/1.3263704},
  volume       = {21},
  year         = {2009},
}