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Related papers: Azimuthal magnetorotational instability with super…

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The nonaxisymmetric 'kink-type' Tayler instability (TI) of toroidal magnetic fields is studied for conducting incompressible fluids of uniform density between two infinitely long cylinders rotating around the same axis. It is shown that for…

Solar and Stellar Astrophysics · Physics 2015-05-13 G. Ruediger , M. Schultz

It is known that in a hydrodynamic Taylor-Couette system uniform rotation or a rotation law with positive shear ('super-rotation') are linearly stable. It is also known that a conducting fluid under the presence of a sufficiently strong…

Solar and Stellar Astrophysics · Physics 2016-02-17 G. Rüdiger , M. Schultz , M. Gellert , F. Stefani

The magnetorotational instability (MRI) of differential rotation under the simultaneous presence of axial and azimuthal components of the (current-free) magnetic field is considered. For rotation with uniform specific angular momentum the…

Astrophysics · Physics 2009-11-13 Guenther Ruediger , Manfred Schultz

The magnetorotational instability (MRI) in cylindrical Taylor-Couette flow with external helical magnetic field is simulated for infinite and finite aspect ratios. We solve the MHD equations in their small Prandtl number limit and confirm…

Astrophysics · Physics 2008-11-26 Jacek Szklarski , Günther Rüdiger

The nonaxisymmetric Tayler instability of toroidal magnetic fields due to axial electric currents is studied for conducting incompressible fluids between two coaxial cylinders without endplates. The inner cylinder is considered as so thin…

Solar and Stellar Astrophysics · Physics 2015-05-20 G. Ruediger , M. Schultz , M. Gellert

Hollerbach and Rudiger have reported a new type of magnetorotational instability (MRI) in magnetized Taylor-Couette flow in the presence of combined axial and azimuthal magnetic fields. The salient advantage of this "helical'' MRI (HMRI) is…

Astrophysics · Physics 2008-11-26 Wei Liu , Jeremy Goodman , Isom Herron , Hantao Ji

In an earlier paper we showed that the combination of azimuthal magnetic fields and super-rotation in Taylor-Couette flows of conducting fluids can be unstable against non-axisymmetric perturbations if the magnetic Prandtl number of the…

Fluid Dynamics · Physics 2021-05-19 G. Rüdiger , M. Schultz , R. Hollerbach

The linear stability of MHD Taylor-Couette flow of infinite vertical extension is considered for liquid sodium with its small magnetic Prandtl number Pm of order of 10^-5 and an uniform axial magnetic field. The sign of the constant a in…

Astrophysics · Physics 2016-08-16 G. Rüdiger , M. Schultz , D. Shalybkov

We show by means of a perturbative weakly nonlinear analysis that the axisymmetric magnetorotational instability (MRI) of a viscous, resistive, incompressible rotating shear flow in a thin channel gives rise to a real Ginzburg-Landau…

Astrophysics · Physics 2008-11-26 O. M. Umurhan , K. Menou , O. Regev

The linear stability theory of Taylor-Couette flows (unbounded in_z_) is described including magnetic fields, Hall effect or a density stratification in order to prepare laboratory experiments to probe the stability of differential rotation…

Astrophysics · Physics 2007-05-23 Guenther Ruediger

This paper presents numerical linear stability analysis of a cylindrical Taylor-Couette flow of liquid metal carrying axial electric current in a generally helical external magnetic field. Axially symmetric disturbances are considered in…

Fluid Dynamics · Physics 2015-03-30 Jānis Priede

The stability problem of MHD Taylor-Couette flows with toroidal magnetic fields is considered in dependence on the magnetic Prandtl number. Only the most uniform (but not current-free) field with B\_in = B\_out has been considered. For high…

Astrophysics · Physics 2008-09-22 M. Gellert , G. Ruediger

According to Rayleigh's criterion, rotating flows are linearly stable when their specific angular momentum increases radially outward. The celebrated magnetorotational instability opens a way to destabilize those flows, as long as the…

Fluid Dynamics · Physics 2015-11-23 Frank Stefani , Oleg N. Kirillov

A recent paper [R. Hollerbach and G. Rudiger, Phys. Rev. Lett. 95, 124501 (2005)] has shown that the threshold for the onset of the magnetorotational instability (MRI) in a Taylor-Couette flow is dramatically reduced if both axial and…

We study the magneto-rotational instability of an incompressible flow which rotates with angular velocity Omega(r)=a+b/r^2 where r is the radius and $a$ and b are constants. We find that an applied magnetic field destabilises the flow, in…

Astrophysics · Physics 2008-11-26 Ashley P. Willis , Carlo F. Barenghi

We study the saturation near threshold of the axisymmetric magnetorotational instability (MRI) of a viscous, resistive, incompressible fluid in a thin-gap Taylor-Couette configuration. A vertical magnetic field, Keplerian shear and no-slip,…

Astrophysics · Physics 2009-11-13 O. M. Umurhan , O. Regev , K. Menou

We perform a local stability analysis of rotational flows in the presence of a constant vertical magnetic field and an azimuthal magnetic field with a general radial dependence. Employing the short-wavelength approximation we develop a…

Fluid Dynamics · Physics 2014-11-14 Oleg N. Kirillov , Frank Stefani , Yasuhide Fukumoto

The linear marginal instability of an MHD Taylor-Couette flow of infinite vertical extension is considered. For hydrodynamically unstable flows the minimum Reynolds number exists even without a magnetic field, but there are also solutions…

Astrophysics · Physics 2016-08-16 G. Rüdiger

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

We study the magnetorotational instability in cylindrical Taylor-Couette flow, with the (vertically unbounded) cylinders taken to be perfect conductors, and with externally imposed spiral magnetic fields. The azimuthal component of this…

Astrophysics · Physics 2009-11-11 G. Ruediger , R. Hollerbach , M. Schultz , D. A. Shalybkov