Complex spectral properties of non-Hermitian operators: An application to open-flow mixing systems

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Standard

Complex spectral properties of non-Hermitian operators : An application to open-flow mixing systems. / Giona, M.; Cerbelli, S.; Garofalo, F.

I: Europhysics Letters, Vol. 83, Nr. 3, 34001, 01.08.2008.

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Harvard

APA

CBE

MLA

Vancouver

Author

RIS

TY - JOUR

T1 - Complex spectral properties of non-Hermitian operators

T2 - An application to open-flow mixing systems

AU - Giona, M.

AU - Cerbelli, S.

AU - Garofalo, F.

PY - 2008/8/1

Y1 - 2008/8/1

N2 - 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.

AB - 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.

UR - http://www.scopus.com/inward/record.url?scp=78951496047&partnerID=8YFLogxK

U2 - 10.1209/0295-5075/83/34001

DO - 10.1209/0295-5075/83/34001

M3 - Article

AN - SCOPUS:78951496047

VL - 83

JO - Europhysics Letters

JF - Europhysics Letters

SN - 1286-4854

IS - 3

M1 - 34001

ER -