English
Related papers

Related papers: Toroidal field instability and eddy viscosity in T…

200 papers

We discuss the well-posedness of the 'transient eddy current' magneto-quasistatic approximation of Maxwell's initial value problem with bounded and measurable conductivity, with sources, on a domain. We prove existence and uniqueness of…

Analysis of PDEs · Mathematics 2020-02-05 Elisa Francini , Giovanni Franzina , Sergio Vessella

By taking into account the effect of toroidal magnetic field and its correspond heating, we determine the thickness of advection-dominated accretion flows. We consider an axisymetric, rotating, steady viscous-resistive, magnetized accretion…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Maryam Samadi , Shahram Abbassi , Mahdi Khajavi

We study the effect of a turbulent flow of liquid sodium generated in the von K\'arm\'an geometry, on the localized field of a magnet placed close to the frontier of the flow. We observe that the field can be transported by the flow on…

Using the Lagrangian transport analysis for the turbulence momentum, the Reynolds stress gradient can be expressed as a function of the local momentum flux and force terms. From this perspective of an observer moving at the local mean…

Fluid Dynamics · Physics 2024-07-09 T. W. Lee , J. E. Park

The magnetohydrodynamic stability of axially unbounded cylindrical flows is considered which contain a toroidal magnetic background field with the same radial profile as the linear azimuthal velocity. Chandrasekhar (1956) has shown for…

Astrophysics of Galaxies · Physics 2015-09-30 Guenther Ruediger , Manfred Schultz , Frank Stefani , Michael Mond

In the present paper, microcanonical measures for the dynamics of three dimensional (3D) axially symmetric turbulent flows with swirl in a Taylor-Couette geometry are defined, using an analogy with a long-range lattice model. We compute the…

Statistical Mechanics · Physics 2015-06-16 Simon Thalabard , Bérengère Dubrulle , Freddy Bouchet

The Kelvin-Helmholtz (KH) instability of a shear layer with an initially-uniform magnetic field in the direction of flow is studied in the framework of 2D incompressible magnetohydrodynamics with finite resistivity and viscosity using…

Plasma Physics · Physics 2021-03-15 A. E. Fraser , P. W. Terry , E. G. Zweibel , M. J. Pueschel , J. M. Schroeder

For low-Reynolds number shear-flows of neutrally-buoyant suspensions, the shear stress is often modeled using an effective viscosity that depends only on the solid fraction. As the Reynolds number ($Re$) is increased and inertia becomes…

Fluid Dynamics · Physics 2020-12-10 Esperanza Linares-Guerrero , Melany L. Hunt , Roberto Zenit

We numerically compute the flow of an electrically conducting fluid in a Taylor-Couette geometry where the rotation rates of the inner and outer cylinders satisfy $\Omega_o/\Omega_i=(r_o/r_i)^{-3/2}$. In this quasi-Keplerian regime a…

Fluid Dynamics · Physics 2017-10-25 Anna Guseva , Rainer Hollerbach , Ashley P. Willis , Marc Avila

Heat and mass transport is generally closely correlated to momentum transport in shear flows. This so-called Reynolds analogy between advective heat or mass transport and momentum transport hinders efficiency improvements in engineering…

Fluid Dynamics · Physics 2021-02-17 Geert Brethouwer

In this paper, we experimentally study the influence of large-scale Taylor rolls on the small-scale statistics and the flow organization in fully turbulent Taylor-Couette flow {for Reynolds numbers up to $\text{Re}_S=3\times 10^5$}. The…

We investigate the instability and nonlinear saturation of temperature-stratified Taylor-Couette flows in a finite height cylindrical gap and calculate angular-momentum transport in the nonlinear regime. The model is based on an…

Astrophysics · Physics 2009-11-13 M. Gellert , G. Rüdiger

Unlike the power-law model, the Ellis model describes the apparent viscosity of a shear-thinning fluid with no singularity in the limit of a vanishingly small shear stress. In particular, this model matches the Newtonian behaviour when the…

Fluid Dynamics · Physics 2023-02-03 Michele Celli , Antonio Barletta , Pedro V. Brandão

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

We consider the effect of toroidal magnetic fields on hydrodynamically stable Taylor-Couette differential rotation flows. For current-free magnetic fields a nonaxisymmetric m=1 magnetorotational instability arises when the magnetic Reynolds…

Astrophysics · Physics 2008-11-26 G. Ruediger , R. Hollerbach , M. Schultz , D. Elstner

Turbulent viscosity $\nu_t$ and resistivity $\eta_t$ are perhaps the simplest models for turbulent transport of angular momentum and magnetic fields, respectively. The associated turbulent magnetic Prandtl number $Pr_t\equiv \nu_t/\eta_t$…

Fluid Dynamics · Physics 2021-08-18 Xin Bian , Jessica K. Shang , Eric G. Blackman , Gilbert W. Collins , Hussein Aluie

We investigate the large-scale transport of inertial particles. We derive explicit analytic expressions for the eddy diffusivities for generic Stokes times. These latter expressions are exact for any shear flow while they correspond to the…

Fluid Dynamics · Physics 2017-01-11 Simone Boi , Andrea Mazzino , Paolo Muratore-Ginanneschi

The transport of charged particles in various astrophysical environments permeated by magnetic fields is described in terms of a diffusion process, which relies on diffusion-tensor parameters generally inferred from Monte-Carlo simulations.…

High Energy Astrophysical Phenomena · Physics 2022-12-09 Olivier Deligny

We interpret measurements of the Reynolds number dependence of the torque in Taylor-Couette flow by Lewis and Swinney [Phys. Rev. E 59, 5457 (1999)] and of the pressure drop in pipe flow by Smits and Zagarola, [Phys. Fluids 10, 1045 (1998)]…

Chaotic Dynamics · Physics 2009-10-31 Bruno Eckhardt , Siegfried Grossmann , Detlef Lohse

We demonstrate a close analogy between a viscoelastic medium and an electrically conducting fluid containing a magnetic field. Specifically, the dynamics of the Oldroyd-B fluid in the limit of large Deborah number corresponds to that of a…

Astrophysics · Physics 2009-11-07 Gordon I. Ogilvie , Michael R. E. Proctor