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Related papers: MHD Turbulence in spin-down flows of liquid metals

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We study the flow structure in 3D magnetohydrodynamic (MHD) simulations of accretion onto Sagittarius A* via the magnetized winds of the orbiting Wolf-Rayet stars. These simulations cover over 3 orders of magnitude in radius to reach…

High Energy Astrophysical Phenomena · Physics 2020-01-29 Sean M. Ressler , Eliot Quataert , James M. Stone

Outflows play a pivotal role in star formation as one of its most visible markers and a means of transporting mass, momentum, and angular momentum from the infalling gas into the surrounding molecular cloud. Their wide reach (at least…

Solar and Stellar Astrophysics · Physics 2024-03-18 Shantanu Basu , Mahmoud Sharkawi , Masahiro N. Machida

The first galaxies form due to gravitational collapse of primordial halos. During this collapse, weak magnetic seed fields get amplified exponentially by the small-scale dynamo - a process converting kinetic energy from turbulence into…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Jennifer Schober , Dominik R. G. Schleicher , Ralf S. Klessen , Christoph Federrath , Stefano Bovino , Simon Glover , Robi Banerjee

The stability of the flow under the magnetic force is one of the classical problems in fluid mechanics. In this paper, the flow in a rectangular duct with different Hartmann (Ha) number is simulated. The finite volume method and the SIMPLE…

Fluid Dynamics · Physics 2019-02-08 Rahman Anisur , Wenqia Xu , Kunhang Li , Hua-Shu Dou , Boo Cheong Khoo , Jie Mao

Initial results from simulations of 4-fluid MHD turbulence in molecular clouds are presented. The species included in the simulations are ions, electrons, negatively charged dust grains and neutrals. The results indicate that, on length…

Astrophysics of Galaxies · Physics 2012-08-02 Turlough P. Downes

Differentially rotating flows of unmagnetized, highly conducting plasmas have been created in the Plasma Couette Experiment. Previously, hot-cathodes have been used to control plasma rotation by a stirring technique [C. Collins et al.,…

We analyze direct numerical simulations of large-scale dynamos in inhomogeneous nonhelically driven rotating turbulence with and without shear. The forcing is modulated so that the turbulent intensity peaks in the middle of the…

Plasma Physics · Physics 2025-05-02 Axel Brandenburg , Ethan T. Vishniac

We analyze the nature of dynamo action that produces horizontally averaged magnetic fields in two particular flows that were studied by Roberts (1972, Phil. Trans. R. Soc. A 271, 411), namely his flows II and III. They have zero kinetic…

Solar and Stellar Astrophysics · Physics 2014-04-25 Matthias Rheinhardt , Ebru Devlen , Karl-Heinz Rädler , Axel Brandenburg

We present 3D magnetohydrodynamic (MHD) numerical simulations of the evolution of self--gravitating and weakly magnetized disks with an adiabatic equation of state. Such disks are subject to the development of both the magnetorotational and…

Anti-dynamo modes are usually found in spheromaks plasma devices experiments due to the fact that Cowling anti-dynamo theorem is naturally applied to axisymmetric devices and flows. In this paper full consideration is given to the existence…

Plasma Physics · Physics 2009-02-04 Garcia de Andrade

We show for the first time that sustained turbulence is possible at low magnetic Prandtl number for Keplerian flows with no mean magnetic flux. Our results indicate that increasing the vertical domain size is equivalent to increasing the…

Solar and Stellar Astrophysics · Physics 2016-12-21 Farrukh Nauman , Martin E. Pessah

Previous studies on nonspherical particle-fluid interaction were mostly confined to elongated fiber-like particles, which were observed to induce turbulence drag reduction. However, with the presence of tiny disk-like particles how wall…

Fluid Dynamics · Physics 2022-01-03 Ze Wang , Chun-Xiao Xu , Lihao Zhao

Recent advancements with trapped nano- and micro-particles have enabled the exploration of motional states on unprecedented scales. Rotational degrees of freedom stand out due to their intrinsic non-linearity and their coupling with…

Magnetic fusion devices operate at regimes characterized by extremely high temperatures and low densities, for which the charged particles motion is well described by classical mechanics. This is not true, however, for solid-state metallic…

Plasma Physics · Physics 2015-06-23 Giovanni Manfredi , Jérôme Hurst

We present direct numerical simulations of dynamo action in a forced Roberts flow. The behavior of the dynamo is followed as the mechanical Reynolds number is increased, starting from the laminar case until a turbulent regime is reached.…

Fluid Dynamics · Physics 2015-06-26 P. D. Mininni , D. C. Montgomery

Magnetohydrodynamical (MHD) dynamos emerge in many different astrophysical situations where turbulence is present, but the interaction between large-scale (LSD) and small-scale dynamos (SSD) is not fully understood. We performed a…

To power gamma-ray bursts and other high-energy events, large-scale magnetic fields are required to extract rotational energy from compact objects such as black holes and neutron stars. The magnetorotational instability (MRI) is a key…

High Energy Astrophysical Phenomena · Physics 2025-09-17 Alexis Reboul-Salze , Loren E. Held , Kenta Kiuchi

We present the first demonstration of the negative effective magnetic pressure instability in direct numerical simulations of stably stratified, externally forced, isothermal hydromagnetic turbulence in the regime of large plasma beta. By…

Solar and Stellar Astrophysics · Physics 2011-10-05 Axel Brandenburg , Koen Kemel , Nathan Kleeorin , Dhrubaditya Mitra , Igor Rogachevskii

The small-scale dynamo is typically studied by assuming that the correlation time of the velocity field is zero. Some authors have used a smooth renovating flow model to study how the properties of the dynamo are affected by the correlation…

Astrophysics of Galaxies · Physics 2024-05-01 Kishore Gopalakrishnan , Nishant K Singh

Magnetic skyrmions, topologically stabilized chiral magnetic textures with particle-like properties have so far primarily been studied statically. Here, we experimentally investigate the dynamics of skyrmion ensembles in metallic thin film…

Mesoscale and Nanoscale Physics · Physics 2024-03-14 Klaus Raab , Maurice Schmitt , Maarten A. Brems , Jan Rothörl , Fabian Kammerbauer , Sachin Krishnia , Mathias Kläui , Peter Virnau