Multiple-scale analysis and renormalization for pre-asymptotic scalar transport

dc.creatorMazzino, A.
dc.creatorMusacchio, S.
dc.creatorVulpiani, A.
dc.date2004-12-01
dc.date.accessioned2026-07-07T05:36:07Z
dc.date.available2026-07-07T05:36:07Z
dc.descriptionPre-asymptotic transport of a scalar quantity passively advected by a velocity field formed by a large-scale component superimposed to a small-scale fluctuation is investigated both analytically and by means of numerical simulations. Exploiting the multiple-scale expansion one arrives at a Fokker--Planck equation which describes the pre-asymptotic scalar dynamics. Such equation is associated to a Langevin equation involving a multiplicative noise and an effective (compressible) drift. For the general case, no explicit expression for both the effective drift and the effective diffusivity (actually a tensorial field) can be obtained. We discuss an approximation under which an explicit expression for the diffusivity (and thus for the drift) can be obtained. Its expression permits to highlight the important fact that the diffusivity explicitly depends on the large-scale advecting velocity. Finally, the robustness of the aforementioned approximation is checked numerically by means of direct numerical simulations.
dc.descriptionrevtex4, 12 twocolumn pages, 3 eps figures
dc.identifierhttps://arxiv.org/abs/nlin/0412004
dc.identifierhttp://arxiv.org/abs/nlin/0412004
dc.identifierPhys. Rev. E 71, 011113 (2005)
dc.identifierdoi:10.1103/PhysRevE.71.011113
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/80884
dc.subjectChaotic Dynamics
dc.titleMultiple-scale analysis and renormalization for pre-asymptotic scalar transport
dc.typetext

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