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Models for GRB outflows invoke turbulence in relativistically hot magnetized fluids. In order to investigate these conditions we have performed high-resolution three-dimensional numerical simulations of relativistic magneto-hydrodynamical…

High Energy Astrophysical Phenomena · Physics 2011-09-29 Jonathan Zrake , Andrew MacFadyen

We study the intermittency and field-line structure of the MHD turbulence in plasmas with very large magnetic Prandtl numbers. In this regime, which is realized in the interstellar medium, some accretion disks, protogalaxies, galaxy-cluster…

Astrophysics · Physics 2008-11-26 A. Schekochihin , J. Maron , S. Cowley , J. McWilliams

In magnetohydrodynamics (MHD), the magnetic field is evolved by the induction equation and coupled to the gas dynamics by the Lorentz force. We perform numerical smoothed particle magnetohydrodynamics (Spmhd) simulations and study the…

Instrumentation and Methods for Astrophysics · Physics 2015-06-05 F. A. Stasyszyn , K. Dolag , A. M. Beck

Turbulent flow remains a challenging subject, despite extensive efforts to find analytical descriptions. Modeling small scales of motion is crucial for saving time and resources in numerical simulations, particularly in industrial…

Fluid Dynamics · Physics 2025-08-13 Julia Domingues Lemos , Fabio Pereira dos Santos

We present a discrete filter for subgrid-scale (SGS) model, coupled with the discretization corrected particle strength exchange (DC-PSE) method for the simulation of three-dimensional viscous incompressible flow, at high Reynolds flows.…

Fluid Dynamics · Physics 2024-08-13 Anas Obeidat

This article serves as a summary outlining the mathematical entropy analysis of the ideal magnetohydrodynamic (MHD) equations. We select the ideal MHD equations as they are particularly useful for mathematically modeling a wide variety of…

Numerical Analysis · Mathematics 2017-08-14 Dominik Derigs , Gregor J. Gassner , Stefanie Walch , Andrew R. Winters

Different approaches to using data-driven methods for subgrid-scale closure modeling have emerged recently. Most of these approaches are data-hungry, and lack interpretability and out-of-distribution generalizability. Here, we use {online}…

We compare the properties of ordinary strong magnetohydrodynamic (MHD) turbulence in a strongly magnetized medium with the recently discovered viscosity-damped regime. We focus on energy spectra, anisotropy, and intermittency. Our most…

Astrophysics · Physics 2009-11-07 Jungyeon Cho , A. Lazarian , Ethan T. Vishniac

We derive exact solutions of a linear form of the Grad-Shafranov (GS) equation, including incompressible equilibrium flow, using ansatz-based similarity reduction methods. The linearity of the equilibrium equation allows linear combinations…

Plasma Physics · Physics 2016-08-31 Dimitrios A. Kaltsas , George N. Throumoulopoulos

Solutions to the compressible Euler equations in all dimensions have been shown to develop finite-time singularities from smooth initial data such as shocks and cusps. There is an extraordinary list of results on this subject. When the…

Analysis of PDEs · Mathematics 2025-07-10 Jiahong Wu , Fuyi Xu , Xiaoping Zhai

We study the construction of subgrid-scale models for large-eddy simulation of incompressible turbulent flows. In particular, we aim to consolidate a systematic approach of constructing subgrid-scale models, based on the idea that it is…

Fluid Dynamics · Physics 2017-01-30 Maurits H. Silvis , Ronald A. Remmerswaal , Roel Verstappen

We present a model for compressible sub-Alfvenic isothermal magnetohydrodynamic (MHD) turbulence in low-beta plasmas and numerically test it. We separate MHD fluctuations into 3 distinct families - Alfven, slow, and fast modes. We find…

Astrophysics · Physics 2016-08-30 Jungyeon Cho , A. Lazarian

A closure model is presented for large-eddy simulation (LES) based on the three-dimensional variational data assimilation algorithm. The approach aims at reconstructing high-fidelity kinetic energy spectra in coarse numerical simulations by…

Fluid Dynamics · Physics 2024-07-02 Sagy Ephrati , Arnout Franken , Erwin Luesink , Paolo Cifani , Bernard Geurts

We are concerned with the uniform regularity estimates of solutions to the two dimensional compressible non-resistive magnetohydrodynamics (MHD) equations with the no-slip boundary condition on velocity in the half plane. Under the…

Analysis of PDEs · Mathematics 2021-08-31 Xiufang Cui , Shengxin Li , Feng Xie

In the present study, we investigate different data-driven parameterizations for large eddy simulation of two-dimensional turbulence in the \emph{a priori} settings. These models utilize resolved flow field variables on the coarser grid to…

Computational Physics · Physics 2020-01-29 Suraj Pawar , Omer San , Adil Rasheed , Prakash Vedula

Extended magnetohydrodynamics (XMHD) is a fluid plasma model generalizing ideal MHD by taking into account the impact of Hall drift effects and the influence of electron inertial effects. XMHD has a Hamiltonian structure which has received…

Analysis of PDEs · Mathematics 2024-06-26 Christophe Cheverry , Nicolas Besse

In large-eddy simulations of atmospheric boundary layer turbulence, the lumped coefficient in the eddy-diffusion subgrid-scale (SGS) model is known to depend on scale for the case of inert scalars. This scale dependence is predominant near…

Atmospheric and Oceanic Physics · Physics 2016-08-16 Jean-François Vinuesa , Fernando Porté-Agel , Sukanta Basu , Rob Stoll

We consider the free boundary problem for the plasma-vacuum interface in ideal compressible magnetohydrodynamics (MHD). In the plasma region the flow is governed by the usual compressible MHD equations, while in the vacuum region we…

Analysis of PDEs · Mathematics 2015-06-12 Paolo Secchi , Yuri Trakhinin

We report a new finite-difference scheme for two-dimensional magnetohydrodynamics (MHD) simulations, with and without rotation, in unstructured grids with quadrilateral cells. The new scheme is implemented within the code VULCAN/2D, which…

Astrophysics · Physics 2009-11-13 Eli Livne , Luc Dessart , Adam Burrows , Casey A. Meakin

We analyse the anisotropy of homogeneous turbulence in an electrically conducting fluid submitted to a uniform magnetic field, for low magnetic Reynolds number, in the quasi- static approximation. We interpret disagreeing previous…

Fluid Dynamics · Physics 2012-07-23 B. F. N. Favier , F. S. Godeferd , C. Cambon , A. Delache , W. J. T. Bos