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Large-scale coronal plasma evolutions can be adequately described by magnetohydrodynamics (MHD) equations. However, full multi-dimensional MHD simulations require substantial computational resources. Given the low plasma $\beta$ in the…

Solar and Stellar Astrophysics · Physics 2024-04-29 Yuhao Zhou , Xiaohong Li , Rony Keppens

Context: Coronal magnetic null points have been implicated as possible locations for localised heating events in 2D models. We investigate this possibility about fully 3D null points. Aims: We investigate the nature of the fast…

Solar and Stellar Astrophysics · Physics 2012-08-30 J. O. Thurgood , J. A. McLaughlin

Multidimensional hydrodynamical simulations have transformed the study of stellar interiors over the past few decades. Most codes developed during that time use the anelastic approximation, which fixes the thermal structure of simulations…

This study delves into a comprehensive examination of the three-dimensional $(3D)$ incompressible magneto-hydrodynamic $(MHD)$ equations in $H^{1}(\R^{3})$. The modification involves incorporating a power term in the nonlinear convection…

Analysis of PDEs · Mathematics 2025-01-28 Maroua Ltifi

The equations describing a two-component cosmological fluid with linearized density perturbations are investigated in the small wavelength or large $k$ limit. The equations are formulated to include a baryonic component, as well as either a…

Astrophysics · Physics 2009-11-11 R. M. Gailis , N. E. Frankel

The set of equations for magnetohydrodynamic (MHD) waves in a shear flow is consecutively derived. The proposed scenario involves the presence of a self-sustained turbulence and magnetic field. In the framework of Langevin--Burgers approach…

Astrophysics · Physics 2009-05-27 T. M. Mishonov , Y. G. Maneva , Z. D. Dimitrov , T. S. Hristov

We review the conservation laws of magnetohydrodynamics (MHD) in an expanding homogeneous and isotropic Universe that can be applied to the study of early Universe physics during the epoch of radiation domination. The conservation laws for…

General Relativity and Quantum Cosmology · Physics 2026-02-19 Alberto Roper Pol , Antonino Salvino Midiri

This article proposes a review of the analysis of the system of magnetohydrodynamics (MHD). First, we give an account of the modelling asumptions. Then, the results of existence of weak solutions, using the notion of renormalized solutions.…

Analysis of PDEs · Mathematics 2015-09-21 Xavier Blanc , Bernard Ducomet

We address the linear-mode analysis performed near an equilibrium configuration in the fluid rest frame with a dynamical magnetic field perturbed on a constant configuration. We develop a simple and general algorithm for an analytic…

Plasma Physics · Physics 2024-09-30 Zhe Fang , Koichi Hattori , Jin Hu

A weak wave turbulence theory is developed for two-dimensional (2D) magnetohydrodynamics (MHD). We derive and analyze the kinetic equation describing the three-wave interactions of pseudo-Alfv\'en waves. Our analysis is greatly helped by…

Plasma Physics · Physics 2015-06-12 Natalia Tronko , Sergey V. Nazarenko , Sebastien Galtier

We have implemented non-ideal Magneto-Hydrodynamics (MHD) effects in the Adaptive Mesh Refinement (AMR) code RAMSES, namely ambipolar diffusion and Ohmic dissipation, as additional source terms in the ideal MHD equations. We describe in…

Solar and Stellar Astrophysics · Physics 2015-10-22 J. Masson , R. Teyssier , C. Mulet-Marquis , P. Hennebelle , G. Chabrier

We review the numerical techniques for ideal and non-ideal magneto-hydrodynamics (MHD) used in the context of star formation simulations. We outline the specific challenges offered by modeling star forming environments, which are dominated…

Instrumentation and Methods for Astrophysics · Physics 2019-07-22 Romain Teyssier , Benoit Commercon

We present the solitary Alfv\'en wave, an exact nonlinear solution of the ideal magnetohydrodynamic (MHD) equations, and construct a three-dimensional numerical model -- an \emph{Alfv\'enon}. The model is characterized by an unperturbed far…

Solar and Stellar Astrophysics · Physics 2026-02-04 Zesen Huang , Marco Velli , Chen Shi , Yuliang Ding

The small Alfv\'en number (denoted by $\varepsilon$) limit (one type of large parameter limits, i.e. singular limits) in magnetohydrodynamic (abbr. MHD) equations was first proposed by Klainerman--Majda in (Comm. Pure Appl. Math. 34:…

Analysis of PDEs · Mathematics 2025-04-24 Yuan Cai , Xiufang Cui , Fei Jiang , Hao Liu

We have developed a hybrid code GMEC: Gyro-kinetic Magnetohydrodynamics (MHD) Energetic-particle Code that can numerically simulate energetic particle-driven Alfv\'en eigenmodes and energetic particle transport in tokamak plasmas. In order…

Plasma Physics · Physics 2024-02-23 Z. Y. Liu , P. Y. Jiang , S. Y. Liu , L. L. Zhang , G. Y. Fu

Context. Radiation plays a significant role in solar and astrophysical environments as it may constitute a sizeable fraction of the energy density, momentum flux, and the total pressure. Modelling the dynamic interaction between radiation…

Solar and Stellar Astrophysics · Physics 2025-04-16 Nishant Narechania , Rony Keppens , Asif ud-Doula , Nicolas Moens , Jon Sundqvist

The Kelvin-Helmholtz instability serves as a simple, well-defined setup for assessing the accuracy of different numerical methods for solving the equations of hydrodynamics. We use it to extend our previous analysis of the convergence and…

Instrumentation and Methods for Astrophysics · Physics 2020-12-09 Martin Obergaulinger , Miguel-Ángel Aloy

In this paper, the general procedure to solve the General Relativistic Hydrodynamical(GRH) equations with Adaptive-Mesh Refinement (AMR) is presented. In order to achieve, the GRH equations are written in the conservation form to exploit…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Orhan Donmez

Context. An essential facet of turbulence is the space-time intermittency of the cascade of energy that leads to coherent structures of high dissipation. Aims. In this work, we attempt to investigate systematically the physical nature of…

Astrophysics of Galaxies · Physics 2022-08-31 Thibaud Richard , Pierre Lesaffre , Edith Falgarone , Andrew Lehmann

This paper describes the design and implementation of our new multi-group, multi-dimensional radiation hydrodynamics (RHD) code Fornax and provides a suite of code tests to validate its application in a wide range of physical regimes.…

Instrumentation and Methods for Astrophysics · Physics 2019-03-06 M. Aaron Skinner , Joshua C. Dolence , Adam Burrows , David Radice , David Vartanyan