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Related papers: Orbital Advection by Interpolation: A Fast and Acc…

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We present a high-order space-time discretization equipped with fully-discrete entropy stability properties for general choices of volume and surface quadrature rules. The formulation uses flux reconstruction (FR) in the spatial dimension…

Numerical Analysis · Mathematics 2026-04-23 Carolyn M. V. Pethrick , Siva Nadarajah

A black hole accretion is necessarily transonic. In presence of sufficiently high viscosity and cooling effects, a low-angular momentum transonic flow can become a standard Keplerian disc except close to the where hole where it must pass…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Kinsuk Giri , Sudip K. Garain , Sandip K. Chakrabarti

In this study, three-dimensional simulations of a reacting hydrogen jet in supersonic crossflow using a structure-preserving discontinuous Galerkin (DG) formulation are examined. The hydrogen jet, with a momentum flux ratio of five, is…

Fluid Dynamics · Physics 2025-08-13 Cal J. Rising , Eric J. Ching , Ryan F. Johnson

We study super-Eddington accretion flows onto black holes using a global three dimensional radiation magneto-hydrodynamical simulation. We solve the time dependent radiative transfer equation for the specific intensities to accurately…

High Energy Astrophysical Phenomena · Physics 2014-11-14 Yan-Fei Jiang , James M. Stone , Shane W. Davis

A positivity-preserving fractional algorithm is presented for solving the four-equation homogeneous relaxation model (HRM) with an arbitrary number of ideal gases and a liquid governed by the stiffened gas equation of state. The fractional…

Computational Physics · Physics 2022-12-21 Man Long Wong , Jordan B. Angel , Cetin C. Kiris

Magnetic fields play an important role in astrophysics on a wide variety of scales, ranging from the Sun and compact objects to galaxies and galaxy clusters. Here we discuss a novel implementation of ideal magnetohydrodynamics (MHD) in the…

Instrumentation and Methods for Astrophysics · Physics 2015-05-30 Ruediger Pakmor , Andreas Bauer , Volker Springel

In this paper, we present an efficient numerical method to address a thermodynamically consistent gas flow model in porous media involving compressible gas and deformable rock. The accurate modeling of gas flow in porous media often poses…

Numerical Analysis · Mathematics 2026-02-16 Huangxin Chen , Yuxiang Chen , Jisheng Kou , Shuyu Sun

This paper studies the nonlinear evolution of magnetic field turbulence in proximity of steady ideal MHD configurations characterized by a small electric current, a small plasma flow, and approximate flux surfaces, a physical setting that…

Plasma Physics · Physics 2024-09-12 Naoki Sato , Michio Yamada

Hydrodynamic simulations have been used to study accretion disks consisting of counterrotating components with an intervening shear layer(s). Configurations of this type can arise from the accretion of newly supplied counterrotating matter…

Astrophysics · Physics 2009-10-31 O. A. Kuznetsov , R. V. E. Lovelace , M. M. Romanova , V. M. Chechetkin

(Abridged) Infrared high-resolution imaging and interferometry have shown that the dust distribution is frequently elongated along the polar direction of an AGN. To explain these findings, we developed a model scenario for the inner ~30 pc…

Astrophysics of Galaxies · Physics 2018-08-15 B. Vollmer , M. Schartmann , L. Burtscher , F. Marin , S. Hoenig , R. Davies , R. Goosmann

This paper presents the development and analysis of a streamline upwind/Petrov-Galerkin (SUPG) method for the magnetic advection-diffusion problem. A key feature of the method is an SUPG-type stabilization term based on the residuals and…

Numerical Analysis · Mathematics 2025-12-02 Haochen Li , Yangfan Luo , Jindong Wang , Shuonan Wu

In radiatively inefficient, laminar protoplanetary disks, embedded planets can excite a buoyancy response as gas gets deflected vertically near the planet. This results in vertical oscillations that drive a vortensity growth in the planet's…

Earth and Planetary Astrophysics · Physics 2023-08-30 Alexandros Ziampras , Sijme-Jan Paardekooper , Richard P. Nelson

We present a formulation and numerical algorithm to extend the scheme for grey radiation magneto-hydrodynamics (MHD) developed by Jiang (2021) to include the frequency dependence via the multi-group approach. The entire frequency space can…

Instrumentation and Methods for Astrophysics · Physics 2022-09-15 Yan-Fei Jiang

Elastic systems that are spatially heterogeneous in their mechanical response pose special challenges for molecular simulations. Standard methods for sampling thermal fluctuations of a system's size and shape proceed through a series of…

Materials Science · Physics 2015-05-13 Sander Pronk , Phillip L. Geissler

In this paper, we propose, analyze, and test a new fully discrete, efficient, decoupled, stable, and practically second-order time-stepping algorithm for computing MHD ensemble flow averages under uncertainties in the initial conditions and…

Numerical Analysis · Mathematics 2021-01-19 Muhammad Mohebujjaman

Hydrodynamic cosmological simulations at present usually employ either the Lagrangian SPH technique, or Eulerian hydrodynamics on a Cartesian mesh with adaptive mesh refinement. Both of these methods have disadvantages that negatively…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Volker Springel

We present a hybrid particle/grid approach for simulating incompressible fluids on collocated velocity grids. We interchangeably use particle and grid representations of transported quantities to balance efficiency and accuracy. A novel…

Radiation is crucial not only for observing astrophysical objects, but also for transporting energy and momentum. However, accurate on-the-fly radiation transport in astrophysical simulations is challenging and computationally expensive.…

Instrumentation and Methods for Astrophysics · Physics 2025-03-24 Jing-Ze Ma , Rüdiger Pakmor , Stephen Justham , Selma E. de Mink

We model gas inflow patterns onto circumstellar disks and the evolution of the pseudodisk using three-dimensional resistive MHD simulations. Starting from a prestellar core without turbulence and with a misalignment between the initial…

Solar and Stellar Astrophysics · Physics 2026-02-10 Masahiro N. Machida , Shingo Hirano , Shantanu Basu

Diverging supersonic flows are accelerating, as in the case of a de Laval nozzle, and the same concept has been applied for acceleration of magnetohydrodynamic flows in the universe. Here, we study the dynamics of "non-diverging"…

High Energy Astrophysical Phenomena · Physics 2020-03-25 Shuta J. Tanaka , Kenji Toma