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Related papers: Kinematic dynamos and resolution limits for Smooth…

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A new code for astrophysical magnetohydrodynamics (MHD) is described. The code has been designed to be easily extensible for use with static and adaptive mesh refinement. It combines higher-order Godunov methods with the constrained…

Astrophysics · Physics 2009-11-13 James M. Stone , Thomas A. Gardiner , Peter Teuben , John F. Hawley , Jacob B. Simon

We have developed a modified form of the equations of smoothed particle magnetohydrodynamics which are stable in the presence of very steep density gradients. Using this formalism, we have performed simulations of the collapse of magnetised…

Solar and Stellar Astrophysics · Physics 2018-03-29 Benjamin T. Lewis , Matthew R. Bate , Daniel J. Price

We consider the classical problem of kinematic dynamo action in simple steady flows. Due to the adjointness of the induction operator, we show that the growth rate of the dynamo will be exactly the same for two types of magnetic boundary…

Fluid Dynamics · Physics 2013-09-25 B. Favier , M. R. E. Proctor

Simulations of decaying magnetohydrodynamic (MHD) turbulence are performed with a fluid and a kinetic code. The initial condition is an ensemble of long-wavelength, counter-propagating, shear-Alfv\'{e}n waves, which interact and rapidly…

Plasma Physics · Physics 2015-06-04 K. D. Makwana , V. Zhdankin , H. Li , W. Daughton , F. Cattaneo

The small-scale kinematic dynamo in a two-dimensional chaotic flow is studied. The analytic approach is developed in framework of the Kraichnan-Kazantsev model. It is shown that the growth of magnetic field $\bm{B}$ fluctuations stops at…

Chaotic Dynamics · Physics 2016-03-30 Igor Kolokolov

The development of smooth particle magnetohydrodynamic (SPMHD) has significantly improved the simulation of complex astrophysical processes. However, the preservation the solenoidality of the magnetic field is still a severe problem for the…

Instrumentation and Methods for Astrophysics · Physics 2015-06-23 Federico Stasyszyn , Detlef Elstner

We investigate the Kelvin-Helmholtz instability occuring at the interface of a shear flow configuration in 2D compressible magnetohydrodynamics (MHD). The linear growth and the subsequent non-linear saturation of the instability are studied…

Astrophysics · Physics 2009-10-31 R. Keppens , G. Toth , R. H. J. Westermann , J. P. Goedbloed

The magnetohydrodynamic dynamo equation is derived within general relativity, using the covariant 1+3 approach, for a plasma with finite electric conductivity. This formalism allows for a clear division and interpretation of plasma and…

Astrophysics · Physics 2009-11-10 Mattias Marklund , Chris Clarkson

Using direct numerical simulations (DNS), we study laminar and turbulent dynamos in chiral magnetohydrodynamics (MHD) with an extended set of equations that accounts for an additional contribution to the electric current due to the chiral…

We discuss asymptotic solutions of the kinematic $\alpha\omega$-dynamo in a thin disc (slab). Focusing upon the strong dynamo regime, in which the dynamo number $D$ satisfies $|D|\gg1$, we resolve uncertainties in the earlier treatments and…

Solar and Stellar Astrophysics · Physics 2014-07-16 Yameng Ji , Laura Cole , Paul Bushby , Anvar Shukurov

We present a new numerical algorithm to solve the recently derived equations of two-moment cosmic ray hydrodynamics (CRHD). The algorithm is implemented as a module in the moving mesh Arepo code. Therein, the anisotropic transport of cosmic…

High Energy Astrophysical Phenomena · Physics 2021-02-24 Timon Thomas , Christoph Pfrommer , Rüdiger Pakmor

We describe a novel splitting approach to numerical relativistic magnetohydrodynamics (RMHD) designed to expand its applicability to the domain of ultra-high magnetisation (high-$\sigma$). In this approach, the electromagnetic field is…

High Energy Astrophysical Phenomena · Physics 2024-11-18 Serguei Komissarov , David Phillips

A physically consistent approach is considered for defining an external magnetic field as needed in computational fluid dynamics problems involving magnetohydrodynamics (MHD). The approach results in simple analytical formulae that can be…

Fluid Dynamics · Physics 2009-11-25 E. V. Votyakov , S. C. Kassinos , X. Albets-Chico

Many interesting terrestrial and astrophysical scenarios involving magnetic fields can be approached in axial geometry. Even though the Lagrangian smoothed particle hydrodynamics (SPH) technique has been successfully extended to handle…

Instrumentation and Methods for Astrophysics · Physics 2022-07-05 Domingo García-Senz , Robert Wissing , Rubén M. Cabezón

Magnetohydrodynamic (MHD) simulations of subsonic (Mach number~$<1$) turbulence are crucial to our understanding of several processes including oceanic and atmospheric flows, the amplification of magnetic fields in the early universe,…

Fluid Dynamics · Physics 2025-11-14 James Watt , Christoph Federrath , Claudius Birke , Christian Klingenberg

We numerically demonstrate the feasibility of kinematic fast dynamos for a class of time-periodic axisymmetric flows of conducting fluid confined inside a sphere. The novelty of our work is in considering the realistic flows, which are…

Plasma Physics · Physics 2013-09-19 I. V. Khalzov , C. M. Cooper , C. B. Forest

Planet-disk interactions can produce kinematic signatures in protoplanetary disks. While recent observations have detected non-Keplerian gas motions in disks, their origins are still being debated. To explore this, we conduct 3D…

Earth and Planetary Astrophysics · Physics 2024-10-10 Kan Chen , Ruobing Dong

Large-scale magnetic fields are relevant for a number of dynamical processes in accretion disks, including driving turbulence, reconnection events, and launching outflows. Numerical simulations have indicated that the initial strengths and…

High Energy Astrophysical Phenomena · Physics 2025-12-04 Hongzhe Zhou , Yosuke Mizuno , Zhenyu Zhu

The excitation of cosmological perturbations in an anisotropic cosmological model and in the presence of a homogeneous magnetic field has been studied, using the ideal magnetohydrodynamic (MHD) equations. In this case, the system of partial…

Astrophysics · Physics 2009-06-23 K. Kleidis , A. Kuiroukidis , D. B. Papadopoulos , L. Vlahos

The conditions imposed in the paper ['Inertial manifolds and completeness of eigenmodes for unsteady magnetic dynamos', Physica D {\bf 194} (2004) 297-319] on the fluid velocity to guarantee the existence of inertial manifolds for the…

Plasma Physics · Physics 2007-05-23 Manuel Nunez