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Laminar magnetohydrodynamic duct flow in the presence of a magnetic dipole
Author(s) -
Tympel Saskia,
Krasnov Dmitry,
Boeck Thomas,
Schumacher Jörg
Publication year - 2011
Publication title -
pamm
Language(s) - English
Resource type - Journals
ISSN - 1617-7061
DOI - 10.1002/pamm.201110325
Subject(s) - lorentz force , laminar flow , magnetic reynolds number , physics , magnetic field , mechanics , magnetohydrodynamic drive , reynolds number , magnetohydrodynamics , classical mechanics , magnetic dipole , magnetic pressure , magnetization , turbulence , quantum mechanics
We study magnetohydrodynamic flow of a liquid metal in a straight duct. The magnetic field is produced by an exterior magnetic dipole. This basic configuration is of fundamental interest for Lorentz force velocimetry (LFV), where the Lorentz force opposing the relative motion of conducting medium and magnetic field is measured to determine the flow velocity. The Lorentz force acts in equal strength but opposite direction on the flow as well as on the dipole. We are interested in the dependence of the velocity on the flow rate and on strength of the magnetic field as well as on geometric parameters such as distance and position of the dipole relative to the duct. To this end, we perform numerical simulations with an accurate finite‐difference method in the limit of small magnetic Reynolds number, whereby the induced magnetic field is assumed to be small compared with the external applied field. The hydrodynamic Reynolds number is also assumed to be small so that the flow remains laminar. The simulations allow us to quantify the magnetic obstacle effect as a potential complication for local flow measurement with LFV. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)