Effective diffusivity of passive scalars in rotating turbulence

We use direct numerical simulations to compute turbulent transport coefficients for passive scalars in turbulent rotating flows. Effective diffusion coefficients in the directions parallel and perpendicular to the rotation axis are obtained by studying the diffusion of an imposed initial profile for...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Imazio, P.R., Mininni, P.D.
Formato: JOUR
Materias:
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_15393755_v87_n2_p_Imazio
Aporte de:
id todo:paper_15393755_v87_n2_p_Imazio
record_format dspace
spelling todo:paper_15393755_v87_n2_p_Imazio2023-10-03T16:22:44Z Effective diffusivity of passive scalars in rotating turbulence Imazio, P.R. Mininni, P.D. Average concentration Characteristic velocities Effective diffusion Effective diffusion coefficients Effective diffusivities Function of time Mixing length Molecular diffusion Passive scalars Perpendicular diffusion Rotating flow Rotating turbulence Rotation axis Schmidt numbers Spatial fluxes Turbulent transports Mixed convection Diffusion article computer simulation diffusion flow kinetics methodology nonlinear system rotation theoretical model Computer Simulation Diffusion Models, Theoretical Nonlinear Dynamics Rheology Rotation We use direct numerical simulations to compute turbulent transport coefficients for passive scalars in turbulent rotating flows. Effective diffusion coefficients in the directions parallel and perpendicular to the rotation axis are obtained by studying the diffusion of an imposed initial profile for the passive scalar, and calculated by measuring the scalar average concentration and average spatial flux as a function of time. The Rossby and Schmidt numbers are varied to quantify their effect on the effective diffusion. It is found that rotation reduces scalar diffusivity in the perpendicular direction. The perpendicular diffusion can be estimated from mixing length arguments using the characteristic velocities and lengths perpendicular to the rotation axis. Deviations are observed for small Schmidt numbers, for which turbulent transport decreases and molecular diffusion becomes more significant. © 2013 American Physical Society. Fil:Mininni, P.D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_15393755_v87_n2_p_Imazio
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Average concentration
Characteristic velocities
Effective diffusion
Effective diffusion coefficients
Effective diffusivities
Function of time
Mixing length
Molecular diffusion
Passive scalars
Perpendicular diffusion
Rotating flow
Rotating turbulence
Rotation axis
Schmidt numbers
Spatial fluxes
Turbulent transports
Mixed convection
Diffusion
article
computer simulation
diffusion
flow kinetics
methodology
nonlinear system
rotation
theoretical model
Computer Simulation
Diffusion
Models, Theoretical
Nonlinear Dynamics
Rheology
Rotation
spellingShingle Average concentration
Characteristic velocities
Effective diffusion
Effective diffusion coefficients
Effective diffusivities
Function of time
Mixing length
Molecular diffusion
Passive scalars
Perpendicular diffusion
Rotating flow
Rotating turbulence
Rotation axis
Schmidt numbers
Spatial fluxes
Turbulent transports
Mixed convection
Diffusion
article
computer simulation
diffusion
flow kinetics
methodology
nonlinear system
rotation
theoretical model
Computer Simulation
Diffusion
Models, Theoretical
Nonlinear Dynamics
Rheology
Rotation
Imazio, P.R.
Mininni, P.D.
Effective diffusivity of passive scalars in rotating turbulence
topic_facet Average concentration
Characteristic velocities
Effective diffusion
Effective diffusion coefficients
Effective diffusivities
Function of time
Mixing length
Molecular diffusion
Passive scalars
Perpendicular diffusion
Rotating flow
Rotating turbulence
Rotation axis
Schmidt numbers
Spatial fluxes
Turbulent transports
Mixed convection
Diffusion
article
computer simulation
diffusion
flow kinetics
methodology
nonlinear system
rotation
theoretical model
Computer Simulation
Diffusion
Models, Theoretical
Nonlinear Dynamics
Rheology
Rotation
description We use direct numerical simulations to compute turbulent transport coefficients for passive scalars in turbulent rotating flows. Effective diffusion coefficients in the directions parallel and perpendicular to the rotation axis are obtained by studying the diffusion of an imposed initial profile for the passive scalar, and calculated by measuring the scalar average concentration and average spatial flux as a function of time. The Rossby and Schmidt numbers are varied to quantify their effect on the effective diffusion. It is found that rotation reduces scalar diffusivity in the perpendicular direction. The perpendicular diffusion can be estimated from mixing length arguments using the characteristic velocities and lengths perpendicular to the rotation axis. Deviations are observed for small Schmidt numbers, for which turbulent transport decreases and molecular diffusion becomes more significant. © 2013 American Physical Society.
format JOUR
author Imazio, P.R.
Mininni, P.D.
author_facet Imazio, P.R.
Mininni, P.D.
author_sort Imazio, P.R.
title Effective diffusivity of passive scalars in rotating turbulence
title_short Effective diffusivity of passive scalars in rotating turbulence
title_full Effective diffusivity of passive scalars in rotating turbulence
title_fullStr Effective diffusivity of passive scalars in rotating turbulence
title_full_unstemmed Effective diffusivity of passive scalars in rotating turbulence
title_sort effective diffusivity of passive scalars in rotating turbulence
url http://hdl.handle.net/20.500.12110/paper_15393755_v87_n2_p_Imazio
work_keys_str_mv AT imaziopr effectivediffusivityofpassivescalarsinrotatingturbulence
AT mininnipd effectivediffusivityofpassivescalarsinrotatingturbulence
_version_ 1807316436130988032