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 perturbation analysis and functional-theoretical arguments is used to explain the occurrence and the range of existence of each regime.
Original language | English |
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Article number | 34001 |
Journal | Europhysics Letters |
Volume | 83 |
Issue number | 3 |
DOIs | |
Publication status | Published - 2008 Aug 1 |
Externally published | Yes |
Subject classification (UKÄ)
- Physical Sciences