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Magnetohydrodynamic Simulations (magnetohydrodynamic + simulation)
Selected AbstractsMagnetohydrodynamic Simulation of Tungsten Wire in Wire-Array Z PinchCONTRIBUTIONS TO PLASMA PHYSICS, Issue 2 2010D.-K. Kim Abstract The magnetohydrodynamic behavior of tungsten wire ablating in wire-array Z pinch discharge on MAGPIE is simulated in a two-dimensional fine-grid domain using the GORGON code. A nonideal resistivity model has been implemented in the simulation to obtain plasma transport coefficients in the high density regime along with a screened hydrogenic model to calculate the radiative cooling. Starting from the initial state of warm dense plasma, the evolution of ablated wire is demonstrated to show its explosion and implosion dynamics as a function of discharge time and then the computed profile of electron density is compared with the contour lines reproduced from the measurement by a laser interferometer during the early stage of discharge. The comparison overall shows a fair agreement in terms of the magnitude and the profile shape while some discrepancies can be attributed to the simplified description of the internal wire core physics (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] General relativistic magnetohydrodynamic simulations of monopole magnetospheres of black holesMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2004S. S. Komissarov ABSTRACT In this paper, we report on the results of the first ever time-dependent general relativistic magnetohydrodynamic simulations of the magnetically dominated monopole magnetospheres of black holes. It is found that the numerical solution evolves towards a stable steady-state solution which is very close to the corresponding force-free solution found by Blandford & Znajek. Contrary to the recent claims, the particle inertia does not become dynamically important near the event horizon and the force-free approximation provides a proper framework for magnetically dominated magnetospheres of black holes. For the first time, our numerical simulations show the development of an ultrarelativistic particle wind from a rotating black hole. However, the flow remains Poynting-dominated all the way up to the fast critical point. This suggests that the details of the so-called ,astrophysical load', where the electromagnetic energy is transferred to particles, may have no effect on the efficiency of the Blandford,Znajek mechanism. [source] Formation of large-scale magnetic-towers in quasarsASTRONOMISCHE NACHRICHTEN, Issue 5-6 2006Y. Kato Abstract The evolution of accretion disks and the formation of jets around super-massive black holes are studied by 3-D magnetohydrodynamic simulations. The previous studies of astrophysical jets have been concentrated on the effects of large-scale magnetic fields permeating accretion disks. However, the existence of such global magnetic fields is not evident in astrophysical objects, and their origin is not well understood. Instead, we concentrate on the effect of the magnetic fields amplified as a result of the magneto-rotational instability in the differentially rotating disk. In our simulations, we found the emergence of accumulated toroidal magnetic fields from the inner region of the disk (a so-called magnetic-tower) and also the formation of jets accelerated by the magnetic pressure of the magnetic-tower. The magnetic energy, ejected by the magnetic-tower jet during a lifetime of an active galactic nuclei (AGNs), is about 1046 erg. Our results indicate that the magnetic-tower jet can be one of the most powerful process for the formation and the evolution of the large-scale structured magnetic .elds in the cluster of galaxies. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] | ||||||||||