Circulation conservation and vortex breakup in magnetohydrodynamics at low magnetic Prandtl number
نویسندگان
چکیده
منابع مشابه
Inverse cascades and α-effect at low magnetic Prandtl number
Dynamo action in a fully helical Beltrami (ABC) flow is studied using both direct numerical simulations and subgrid modeling. Sufficient scale separation is given in order to allow for largescale magnetic energy build-up. Growth of magnetic energy obtains down to a magnetic Prandtl number PM = RM/RV close to 0.005, where RV and RM are the kinetic and magnetic Reynolds numbers. The critical magn...
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The dynamo instability is investigated in the limit of infinite magnetic Prandtl number. In this limit the fluid is assumed to be very viscous so that the inertial terms can be neglected and the flow is enslaved to the forcing. The forcing consist of an external forcing function that drives the dynamo flow and the resulting Lorentz force caused by the back reaction of the magnetic field. The fl...
متن کاملdynamo at low magnetic Prandtl numbers
We investigate the dynamo problem in the limit of small magnetic Prandtl number (Pm) using a shell model of magnetohydrodynamic turbulence. The model is designed to satisfy conservation laws of total energy, cross helicity and magnetic helicity in the limit of inviscid fluid and null magnetic diffusivity. The forcing is chosen to have a constant injection rate of energy and no injection of kine...
متن کاملDissipation in dynamos at low and high magnetic Prandtl numbers
Using simulations of helically driven turbulence, it is shown that the ratio of kinetic to magnetic energy dissipation scales with the magnetic Prandtl number in power law fashion with an exponent of approximately 0.6. Over six orders of magnitude in the magnetic Prandtl number the magnetic field is found to be sustained by large-scale dynamo action of alphasquared type. This work extends a sim...
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A phenomenology of isotropic magnetohydrodynamic (MHD) turbulence subject to both rotation and applied magnetic field is presented. It is assumed that the triple correlation decay time is the shortest between the eddy turn-over time and the ones associated to the rotating frequency and the Alfvén wave period. For Pm=1 it leads to four kinds of piecewise spectra, depending on four parameters: in...
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ژورنال
عنوان ژورنال: Journal of Fluid Mechanics
سال: 2018
ISSN: 0022-1120,1469-7645
DOI: 10.1017/jfm.2018.719