Complex spectral properties of non-Hermitian operators : An application to open-flow mixing systems
(2008) In Europhysics Letters 83(3).- Abstract
We study the spectral properties of the advection-diffusion operator associated with a non-chaotic 3d Stokes flow defined in the annular region between counter-rotating cylinders of finite length. The focus is on the dependence of the eigenvalue-eigenfunction spectrum on the Peclet number Pe. Several convection-enhanced mixing regimes are identified, each characterized by a power law scaling, -μd∼Pe-γ (γd, vs.Pe. Among these regimes, a Pe-independent scaling -μd=const (i.e., γ=0), qualitatively similar to the asymptotic regime of globally chaotic flows, is observed. This regime arises as the consequence of different eigenvalues branches interchanging dominance at increasing Pe. A combination of... (More)
We study the spectral properties of the advection-diffusion operator associated with a non-chaotic 3d Stokes flow defined in the annular region between counter-rotating cylinders of finite length. The focus is on the dependence of the eigenvalue-eigenfunction spectrum on the Peclet number Pe. Several convection-enhanced mixing regimes are identified, each characterized by a power law scaling, -μd∼Pe-γ (γd, vs.Pe. Among these regimes, a Pe-independent scaling -μd=const (i.e., γ=0), qualitatively similar to the asymptotic regime of globally chaotic flows, is observed. This regime arises as the consequence of different eigenvalues branches interchanging dominance at increasing Pe. A combination of perturbation analysis and functional-theoretical arguments is used to explain the occurrence and the range of existence of each regime.
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- author
- Giona, M. ; Cerbelli, S. and Garofalo, F. LU
- publishing date
- 2008-08-01
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Europhysics Letters
- volume
- 83
- issue
- 3
- article number
- 34001
- publisher
- EDP Sciences
- external identifiers
-
- scopus:78951496047
- ISSN
- 0295-5075
- DOI
- 10.1209/0295-5075/83/34001
- language
- English
- LU publication?
- no
- id
- 9cbaffc9-0b12-48b5-9f88-62d30786600f
- date added to LUP
- 2016-06-27 10:11:17
- date last changed
- 2022-03-16 06:49:51
@article{9cbaffc9-0b12-48b5-9f88-62d30786600f, abstract = {{<p>We study the spectral properties of the advection-diffusion operator associated with a non-chaotic 3d Stokes flow defined in the annular region between counter-rotating cylinders of finite length. The focus is on the dependence of the eigenvalue-eigenfunction spectrum on the Peclet number Pe. Several convection-enhanced mixing regimes are identified, each characterized by a power law scaling, -μ<sub>d</sub>∼Pe<sup>-γ</sup> (γd, vs.Pe. Among these regimes, a Pe-independent scaling -μ<sub>d</sub>=const (i.e., γ=0), qualitatively similar to the asymptotic regime of globally chaotic flows, is observed. This regime arises as the consequence of different eigenvalues branches interchanging dominance at increasing Pe. A combination of perturbation analysis and functional-theoretical arguments is used to explain the occurrence and the range of existence of each regime.</p>}}, author = {{Giona, M. and Cerbelli, S. and Garofalo, F.}}, issn = {{0295-5075}}, language = {{eng}}, month = {{08}}, number = {{3}}, publisher = {{EDP Sciences}}, series = {{Europhysics Letters}}, title = {{Complex spectral properties of non-Hermitian operators : An application to open-flow mixing systems}}, url = {{http://dx.doi.org/10.1209/0295-5075/83/34001}}, doi = {{10.1209/0295-5075/83/34001}}, volume = {{83}}, year = {{2008}}, }