Observation of a Free-Shercliff-Layer Instability in Cylindrical Geometry

Abstract

We report on observations of a free-Shercliff-layer instability in a Taylor-Couette experiment using a liquid metal over a wide range of Reynolds numbers, $Re\sim 10^3-10^6$. The free Shercliff layer is formed by imposing a sufficiently strong axial magnetic field across a pair of differentially rotating axial endcap rings. This layer is destabilized by a hydrodynamic Kelvin-Helmholtz-type instability, characterized by velocity fluctuations in the $r-\theta$ plane. The instability appears with an Elsasser number above unity, and saturates with an azimuthal mode number $m$ which increases with the Elsasser number. Measurements of the structure agree well with 2D global linear mode analyses and 3D global nonlinear simulations. These observations have implications for a range of rotating MHD systems in which similar shear layers may be produced.

5 pages, 4 figures

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Cited by in corpus (19)

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• Numerical simulations of the Princeton magneto-rotational instability experiment with conducting axial boundaries
• Modes and instabilities in magnetized spherical Couette flow
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• Identification of a non-axisymmetric mode in laboratory experiments searching for standard magnetorotational instability
• Weakly magnetized, Hall dominated plasma Couette flow
• Taylor-Couette flow for astrophysical purposes
• Reynolds number scaling of influence of boundary layers on the global behavior of laboratory quasi-Keplerian flows
• Generalised quasi-linear approximation of the HMRI
• Turbulence in electromagnetically-driven Keplerian flows
• Quasi-two-dimensional nonlinear evolution of helical magnetorotational instability in a magnetized Taylor-Couette flow
• Ion heating and flow driven by an Instability found in Plasma Couette Flow
• Magnetic field dynamos and magnetically triggered flow instabilities
• Absolute versus convective helical magnetorotational instabilities in Taylor-Couette flows
• Laboratory modeling of MHD accretion disks
• Shercliff layers in strongly magnetic cylindrical Taylor-Couette flow
• Transition to turbulence in ferrofluids
• Angular Momentum Transport by Keplerian Turbulence in Liquid Metals
• Laboratory experiments and numerical simulations on magnetic instabilities