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Related papers: Particle-Gas Dynamics with Athena: Method and Conv…

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This work describes a new 1D hybrid approach for modeling atmospheric pressure discharges featuring complex chemistry. In this approach electrons are described fully kinetically using Particle-In-Cell/Monte-Carlo (PIC/MCC) scheme, whereas…

Plasma Physics · Physics 2016-01-20 Denis Eremin , Torben Hemke , Thomas Mussenbrock

We present a method for simulating the evolution of HII regions driven by point sources of ionizing radiation in magnetohydrodynamic media, implemented in the three-dimensional Athena MHD code. We compare simulations using our algorithm to…

Astrophysics · Physics 2009-11-11 Mark R. Krumholz , James M. Stone , Thomas A. Gardiner

We present a simple route to obtain large quantities of suspensions of non-Brownian particles with stimuli-responsive surface properties to study the relation between their flow and interparticle interactions. We perform an alkaline…

Soft Condensed Matter · Physics 2024-06-25 Lily Blaiset , Bruno Bresson , Ludovic Olanier , Élisabeth Guazzelli , Matthieu Roché , Nicolas Sanson

Piernik is a multi-fluid grid magnetohydrodynamic (MHD) code based on the Relaxing Total Variation Diminishing (RTVD) conservative scheme. The original code has been extended by addition of dust described within the particle approximation.…

Earth and Planetary Astrophysics · Physics 2016-08-14 Joanna Drążkowska , Michał Hanasz , Kacper Kowalik

Grid-based magnetohydrodynamic (MHD) simulations have proven invaluable for the study of astrophysical accretion disks. However, the fact that angular momentum transport in disks is mediated by MHD turbulence (with structure down to very…

High Energy Astrophysical Phenomena · Physics 2015-05-28 Kareem A. Sorathia , Christopher S. Reynolds , James M. Stone , Kris Beckwith

Computational fluid dynamics is a crucial tool to theoretically explore the cosmos. In the last decade, we have seen a substantial methodological diversification with a number of cross-fertilizations between originally different methods.…

Instrumentation and Methods for Astrophysics · Physics 2023-01-25 Stephan Rosswog

In many astrophysical plasmas, the Coulomb collision is insufficient to maintain an isotropic temperature, and the system is driven to the anisotropic regime. In this case, magnetohydrodynamic (MHD) models with anisotropic pressure are…

Plasma Physics · Physics 2023-08-09 Hongyang Luo , John G. Lyon , Binzheng Zhang

We present the extension of GR-Athena++ to general-relativistic magnetohydrodynamics (GRMHD) for applications to neutron star spacetimes. The new solver couples the constrained transport implementation of Athena++ to the Z4c formulation of…

General Relativity and Quantum Cosmology · Physics 2023-11-10 William Cook , Boris Daszuta , Jacob Fields , Peter Hammond , Simone Albanesi , Francesco Zappa , Sebastiano Bernuzzi , David Radice

In this paper, we consider mathematical modeling and numerical simulation of non-isothermal compressible multi-component diffuse-interface two-phase flows with realistic equations of state. A general model with general reference velocity is…

Numerical Analysis · Mathematics 2018-08-15 Jisheng Kou , Shuyu Sun

We present a novel implementation of Smoothed Particle Hydrodynamics (SPHS) that uses the spatial derivative of the velocity divergence as a higher order dissipation switch. Our switch -- which is second order accurate -- detects flow…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 J. I. Read , T. Hayfield

In a companion paper we have shown how the equations describing gas and dust as two fluids coupled by a drag term can be reformulated to describe the system as a single fluid mixture. Here we present a numerical implementation of the…

Earth and Planetary Astrophysics · Physics 2015-06-18 Guillaume Laibe , Daniel J. Price

Stars and planets move supersonically in a gaseous medium during planetary engulfment, stellar interactions and within protoplanetary disks. For a nearly uniform medium, the relevant parameters are the Mach number and the size of the body,…

Solar and Stellar Astrophysics · Physics 2023-11-01 Logan J. Prust , Lars Bildsten

The assumption of a spatially uniform helium distribution in the intracluster medium can lead to biases in the estimates of key cluster parameters if composition gradients are present. The helium concentration profile in galaxy clusters is…

High Energy Astrophysical Phenomena · Physics 2020-06-04 Thomas Berlok , Martin E. Pessah

We perform experiments with a granular system that consists of a collection of identical hollow spheres (ping-pong balls). Particles rest on a horizontal metallic grid and are confined within a circular region. Fluidization is achieved by…

The aim of this work is to investigate and characterise particle behaviour in an (observationally-driven) 3D MHD model of the solar atmosphere above a slowly evolving, non-flaring active region. We use a relativistic guiding-centre particle…

Solar and Stellar Astrophysics · Physics 2016-02-17 J. Threlfall , Ph. -A. Bourdin , T. Neukirch , C. E. Parnell

We discuss the ability of the smoothed particle hydrodynamics (SPH) method combined with a grid-based solver for the Poisson equation to model mass accretion onto protostars in gravitationally unstable protostellar discs. We scrutinize…

Earth and Planetary Astrophysics · Physics 2018-09-06 Olga P. Stoyanovskaya , Nikolay V. Snytnikov , Valeriy N. Snytnikov

This paper presents a numerical study of flow through static random assemblies of monodisperse, spherical particles. A lattice Boltzmann approach based on a two relaxation time collision operator is used to obtain reliable predictions of…

Fluid Dynamics · Physics 2014-10-08 Simon Bogner , Swati Mohanty , Ulrich Rüde

This work is devoted to the consistent modeling of a three-phase mixture of a gas, a liquid and its vapor. Since the gas and the vapor are mis-cible, the mixture is subjected to a non-symmetric constraint on the volume. Adopting the Gibbs…

Analysis of PDEs · Mathematics 2017-10-13 Hélène Mathis

We report a detailed computational study by Brownian Dynamics simulations of the structure and dynamics of a liquid of patchy particles which develops an amorphous tetrahedral network upon decreasing temperature. The highly directional…

Soft Condensed Matter · Physics 2016-12-02 Sandalo Roldan-Vargas , Lorenzo Rovigatti , Francesco Sciortino

This paper mainly considers three iterations based on charge-conservative finite element approximation in Lipschitz domain for the stationary thermally coupled inductionless MHD equations. Based on the hybrid finite element method, the…

Analysis of PDEs · Mathematics 2023-03-22 Shitian Dong , Haiyan Su