English
Related papers

Related papers: Transport coefficients for the shear dynamo proble…

200 papers

We study the shear viscosity in an effective hydrodynamic theory and holographic model where the translational symmetry is broken by massless scalar fields. We identify the shear viscosity, $\eta$, from the coefficient of the shear tensor…

High Energy Physics - Theory · Physics 2016-11-09 Piyabut Burikham , Napat Poovuttikul

We calculate the transport coefficient of hadronic matter in the presence of temperature and magnetic field using the linear sigma model. In the relaxation time approximation, we estimate the shear viscosity over entropy density $\eta/s$.…

High Energy Physics - Phenomenology · Physics 2022-06-22 Ritesh Ghosh , Najmul Haque

A rigorous theory for the generation of a large-scale magnetic field by random non-helically forced motions of a conducting fluid combined with a linear shear is presented in the analytically tractable limit of low Rm and weak shear. The…

Astrophysics · Physics 2011-12-15 T. Heinemann , J. C. McWilliams , A. A. Schekochihin

The small-scale dynamo is typically studied by assuming that the correlation time of the velocity field is zero. Some authors have used a smooth renovating flow model to study how the properties of the dynamo are affected by the correlation…

Astrophysics of Galaxies · Physics 2024-05-01 Kishore Gopalakrishnan , Nishant K Singh

This paper deals with collisionless transport equations in bounded open domains $\Omega \subset \R^{d}$ $(d\geq 2)$ with $\mathcal{C}^{1}$ boundary $\partial \Omega $, orthogonally invariant velocity measure $\bm{m}(\d v)$ with support…

Analysis of PDEs · Mathematics 2019-04-09 Bertrand Lods , Mustapha Mokhtar-Kharroubi , Ryszard Rudnicki

We numerically solve the magnetic induction equation in a spherical shell geometry, with a kinematically prescribed axisymmetric flow that consists of a superposition of a small-scale helical flow and a large-scale shear flow. The…

Plasma Physics · Physics 2016-09-20 Aditi Sood , Rainer Hollerbach , Eun-jin Kim

This work presents numerical results on the transport of heat and chemical species by shear-induced turbulence in strongly stratified but thermally diffusive environments. The shear instabilities driven in this regime are sometimes called…

Solar and Stellar Astrophysics · Physics 2016-04-20 Pascale Garaud , Logithan Kulenthirarajah

We investigate dynamo action in global compressible solar-like convective dynamos in the framework of mean-field theory. We simulate a solar-type star in a wedge-shaped spherical shell, where the interplay between convection and rotation…

Solar and Stellar Astrophysics · Physics 2018-01-17 Jörn Warnecke , Matthias Rheinhardt , S. Tuomisto , Petri J. Käpylä , Maarit J. Käpylä , Axel Brandenburg

This letter investigates the transport properties of MHD turbulence induced by the magnetorotational instability at large Reynolds numbers Re when the magnetic Prandtl number Pm is larger than unity. Three MHD simulations of the…

High Energy Astrophysical Phenomena · Physics 2016-12-07 Sebastien Fromang

We have studied the momentum transport properties of a hot and dense QCD matter in the presence of weak magnetic field by determining the shear ($\eta$) and bulk ($\zeta$) viscosities in the relaxation time approximation of kinetic theory.…

High Energy Physics - Phenomenology · Physics 2022-09-21 Shubhalaxmi Rath , Sadhana Dash

It is widely accepted that astrophysical magnetic fields are generated by dynamo action. In many cases these fields exhibit organisation on a scale larger than that of the underlying turbulent flow (e.g., the eleven-year solar cycle). The…

Fluid Dynamics · Physics 2018-12-03 Laura K. Currie , Steven M. Tobias

The effect of a dynamo-generated mean magnetic field of Beltrami type on the mean electromotive force is studied. In the absence of the mean magnetic field the turbulence is assumed to be homogeneous and isotropic, but it becomes…

Astrophysics · Physics 2008-10-20 A. Brandenburg , K. -H. Rädler , M. Rheinhardt , K. Subramanian

Small scale turbulent dynamo action in compressible transonic turbulence is discussed. It is shown that the critical value of the magnetic Reynolds number displays a bimodal behavior and changes from a typical value of 35 for small Mach…

Astrophysics · Physics 2007-05-23 A. Brandenburg , N. E. L. Haugen , A. J. Mee

The Reynolds transport theorem for the rate of change of an integral over an evolving domain is generalized. For a manifold $B$, a differentiable motion $m$ of $B$ in the manifold $\mathcal{S}$, an $r$-current $T$ in $B$, and the sequence…

Mathematical Physics · Physics 2014-03-25 Lior Falach , Reuven Segev

Starting from the Boltzmann equation in the relaxation time approximation and employing a Chapman-Enskog like expansion for the distribution function close to equilibrium, we derive second-order evolution equations for the shear stress…

Nuclear Theory · Physics 2015-11-18 Amaresh Jaiswal , Bengt Friman , Krzysztof Redlich

Transport of scalar fields in compressible flow is investigated. The effective equations governing the transport at scales large compared to those of the advecting flow are derived by using multi-scale techniques. Ballistic transport…

chao-dyn · Physics 2009-10-28 M. Vergassola , M. Avellaneda

We demonstrate with a nonlinear MHD code that angular momentum can be transported due to the magnetic instability of toroidal fields under the influence of differential rotation, and that the resulting effective viscosity may be high enough…

Solar and Stellar Astrophysics · Physics 2015-06-19 G. Ruediger , M. Gellert , F. Spada , I. Tereshin

Using particle-scale simulations of non-suspended sediment transport for a large range of Newtonian fluids driving transport, including air and water, we determine the bulk transport cessation threshold $\Theta^r_t$ by extrapolating the…

Atmospheric and Oceanic Physics · Physics 2019-09-17 Thomas Pähtz , Orencio Durán

Visco-resistive magnetohydrodynamic turbulence, driven by a two-dimensional unstable shear layer that is maintained by an imposed body force, is examined by decomposing it into dissipationless linear eigenmodes of the initial profiles. The…

Fluid Dynamics · Physics 2022-09-14 B. Tripathi , A. E. Fraser , P. W. Terry , E. G. Zweibel , M. J. Pueschel

In this study we present a compressible test-field method (CTFM) for computing $\alpha$ effect and turbulent magnetic diffusivity tensors, as well as those relevant for mean ponderomotive force and mass source, applied to the full MHD…

Fluid Dynamics · Physics 2022-06-15 Maarit J. Käpylä , Matthias Rheinhardt , Axel Brandenburg