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Related papers: Energy Fluxes during Dynamo Reversals

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In magnetohydrodynamic (MHD) flows, incompressibility is assumed for low Mach numbers. However, even at low Mach numbers, the Mach number influences flow and magnetic fields. Therefore, it is necessary to develop a method that can stably…

Fluid Dynamics · Physics 2025-12-24 Hideki Yanaoka

To demonstrate the magnetic energy dissipation via relativistic shocks, we carry out spherically symmetrical one-dimensional special relativistic magneto-hydrodynamic simulations of highly magnetised outflows with an adaptive mesh…

High Energy Astrophysical Phenomena · Physics 2023-07-21 Yo Kusafuka , Katsuaki Asano , Takumi Ohmura , Tomohisa Kawashima

We present a three--pronged numerical approach to the dynamo problem at low magnetic Prandtl numbers $P_M$. The difficulty of resolving a large range of scales is circumvented by combining Direct Numerical Simulations, a Lagrangian-averaged…

Geophysics · Physics 2009-11-10 Y. Ponty , P. D. Mininni , D. C. Montgomery , J. -F. Pinton , H. Politano , A. Pouquet

Relativistic magnetic reconnection is a key process for accelerating charged particles and producing high-energy radiation. We study this process using relativistic resistive magnetohydrodynamics simulations. Starting with Harris sheet…

Plasma Physics · Physics 2025-06-23 Harihar Pradhan , Kirit D Makwana , Bart Ripperda

Experiments and numerical simulations show that the energy spectrum of the magnetohydrodynamic turbulence in the quasi-static limit deviates from Kolmogorov's $k^{-5/3}$ spectrum as the external magnetic field, or equivalently the…

Fluid Dynamics · Physics 2013-04-26 Mahendra K. Verma

A numerical study of dynamos in rotating convecting plane layers is presented which focuses on magnetic energies and dissipation rates, and the generation of mean fields (where the mean is taken over horizontal planes). The scaling of the…

Fluid Dynamics · Physics 2015-06-22 A. Tilgner

While the saturated magnetic energy is independent of viscosity in dynamo experiments, it remains viscosity-dependent in state-of-the-art 3D direct numerical simulations (DNS). Extrapolating such viscous scaling-laws to realistic parameter…

Fluid Dynamics · Physics 2017-12-20 Kannabiran Seshasayanan , Basile Gallet , Alexandros Alexakis

In an earlier paper (physics/0006012) we had developed a method for computing the effective energy transfer between any two Fourier modes in fluid or magnetohydrodynamic (MHD) flows. This method is applied to a pseudo-spectral, direct…

chao-dyn · Physics 2007-05-23 Gaurav Dar , Mahendra K. Verma , V. Eswaran

We consider the induction of magnetic field in flows of electrically conducting fluid at low magnetic Prandtl number and large kinetic Reynolds number. Using the separation between the magnetic and kinetic diffusive lengthscales, we propose…

Fluid Dynamics · Physics 2009-11-10 Yannick Ponty , Helene Politano , Jean-Francois Pinton

We analyze the initial, kinematic stage of magnetic field evolution in an isotropic and homogeneous turbulent conducting fluid with a rough velocity field, v(l) ~ l^alpha, alpha<1. We propose that in the limit of small magnetic Prandtl…

Astrophysics · Physics 2007-05-23 Stanislav Boldyrev , Fausto Cattaneo

Magnetohydrodynamic turbulence regulates the transfer of energy from large to small scales in many astrophysical systems, including the solar atmosphere. We perform three-dimensional magnetohydrodynamic simulations with unprecedentedly…

Solar and Stellar Astrophysics · Physics 2023-05-30 Chuanfei Dong , Liang Wang , Yi-Min Huang , Luca Comisso , Timothy A. Sandstrom , Amitava Bhattacharjee

The dissipation of turbulent magnetic fields is an appealing scenario to explain the origin of non-thermal particles in high-energy astrophysical sources. However, it has been suggested that the particle distribution may effectively…

High Energy Astrophysical Phenomena · Physics 2020-01-09 Emanuele Sobacchi , Yuri E. Lyubarsky

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

The non-collisional interaction between conducting obstacles and magnetized plasma winds can be found in different scenarios, from the interaction occurring between regions inside galaxy clusters to the interaction between the solar wind…

Earth and Planetary Astrophysics · Physics 2015-06-22 Norberto Romanelli , Daniel Gomez , Cesar Bertucci , Magda Delva

We use kinetic particle-in-cell and magnetohydrodynamic simulations supported by an observational dataset to investigate magnetic reconnection in clusters of null points in space plasma. The magnetic configuration under investigation is…

Earth and Planetary Astrophysics · Physics 2015-09-29 Vyacheslav Olshevsky , Andrey Divin , Elin Eriksson , Stefano Markidis , Giovanni Lapenta

Based on data obtained from Wilcox Solar Observatiry the solar polar magnetic fields reversals in cycles 21\,--\,25 were considered. The results indicate that the polarity reversal occurs at the maximum of sunspot activity of each cycle,…

Solar and Stellar Astrophysics · Physics 2025-11-03 Irina A. Bilenko

We perform a suite of two- and three-dimensional magnetohydrodynamic (MHD) simulations with the Athena code of the non-driven Kelvin-Helmholtz instability in the subsonic, weak magnetic field limit. Focusing the analysis on the non-linear…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Greg Salvesen , Kris Beckwith , Jacob B. Simon , Sean M. O'Neill , Mitchell C. Begelman

Three-dimensional direct numerical simulations are used to study the energy cascade rate in isothermal compressible magnetohydrodynamic turbulence. Our analysis is guided by a two-point exact law derived recently for this problem in which…

(abidged) Context: Stellar convection zones are characterized by vigorous high-Reynolds number turbulence at low Prandtl numbers. Aims: We study the dynamo and differential rotation regimes at varying levels of viscous, thermal, and…

Solar and Stellar Astrophysics · Physics 2017-02-22 P. J. Käpylä , M. J. Käpylä , N. Olspert , J. Warnecke , A. Brandenburg

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