The mean electromotive force due to turbulence of a conducting fluid in the presence of mean flow

Abstract

The mean electromotive force caused by turbulence of an electrically conducting fluid, which plays a central part in mean--field electrodynamics, is calculated for a rotating fluid. Going beyond most of the investigations on this topic, an additional mean motion in the rotating frame is taken into account. One motivation for our investigation originates from a planned laboratory experiment with a Ponomarenko-like dynamo. In view of this application the second--order correlation approximation is used. The investigation is of high interest in astrophysical context, too. Some contributions to the mean electromotive are revealed which have not been considered so far, in particular contributions to the $\alpha$--effect and related effects due to the gradient of the mean velocity. Their relevance for dynamo processes is discussed. In a forthcoming paper the results reported here will be specified to the situation in the laboratory and partially compared with experimental findings.

16 pages, 2 figures, in PRE press

References in corpus (1)

• Do mean-field dynamos in nonrotating turbulent shear-flows exist?

Cited by in corpus (49)

• Mean-field concept and direct numerical simulations of rotating magnetoconvection and the geodynamo
• Dynamo theories
• Magnetic diffusivity tensor and dynamo effects in rotating and shearing turbulence
• Generation of Magnetic Field by Combined Action of Turbulence and Shear
• Astrophysical turbulence modeling
• Advances in mean-field dynamo theory and applications to astrophysical turbulence
• Mean--field electrodynamics: Critical analysis of various analytical approaches to the mean electromotive force
• Synchronized helicity oscillations: a link between planetary tides and the solar cycle?
• The mean electro-motive force, current- and cross-helicity under the influence of rotation, magnetic field and shear
• Numerical experiments on dynamo action in sheared and rotating turbulence
• Alpha effect and diffusivity in helical turbulence with shear
• Generation of large-scale magnetic fields by small-scale dynamo in shear flows
• Characterisation of the turbulent electromotive force and its magnetically-mediated quenching in a global EULAG-MHD simulation of solar convection
• Shear-current effect in a turbulent convection with a large-scale shear
• Scaling and intermittency in incoherent α-shear dynamo
• The alpha effect in rotating convection with sinusoidal shear
• The shear dynamo problem for small magnetic Reynolds numbers
• Pumping velocity in homogeneous helical turbulence with shear
• Mean-field dynamo in a turbulence with shear and kinetic helicity fluctuations
• Nonperturbative quasilinear approach to the shear dynamo problem
• The supernova-regulated ISM. III. Generation of vorticity, helicity and mean flows
• Electromotive force due to magnetohydrodynamic fluctuations in sheared rotating turbulence
• Transport coefficients for the shear dynamo problem at small Reynolds numbers
• The dual role of shear in large-scale dynamos
• Simulations of the anisotropic kinetic and magnetic alpha effects
• Shear dynamo problem: Quasilinear kinematic theory
• The magnetic shear-current effect: generation of large-scale magnetic fields by the small-scale dynamo
• Coherent nonhelical shear dynamos driven by magnetic fluctuations at low Reynolds numbers
• Stellar dynamos with $\vec{\Omega }\times \vec{J}$ effect
• Numerical studies of dynamo action in a turbulent shear flow - I
• Nonhelical mean-field dynamos in a sheared turbulence
• Nonlinear shear-current dynamo and magnetic helicity transport in sheared turbulence
• Alpha-effect dynamos with zero kinetic helicity
• On large-scale dynamos with stable stratification and the application to stellar radiative zones
• On the shear-current effect: toward understanding why theories and simulations have mutually and separately conflicted
• Large scale fluctuations and dynamics of the Bullard - von Kármán dynamo
• Mean field dynamo action in renovating shearing flows
• Some consequences of shear on galactic dynamos with helicity fluxes
• Dynamo efficiency with shear in helical turbulence
• On the effects of turbulence on a screw dynamo
• Unified treatment of mean-field dynamo and angular-momentum transport in magnetorotational instability-driven turbulence
• Turbulent transport and dynamo in sheared MHD turbulence with a non-uniform magnetic field
• Vorticity and magnetic dynamo from subsonic expansion waves
• The alpha-effect in a turbulent liquid-metal plane Couette flow
• Generalized quenching of large-scale magnetic dynamos in anisotropic flows
• New mechanism of generation of large-scale magnetic field in a sheared turbulent plasma
• Electromotive field in space and astrophysical plasmas
• Analysis of the Effect of a Mean Velocity Field on Mean Field Dynamo
• Calculating turbulent transport tensors by averaging single plume dynamics and application to dynamos