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Related papers: MAESTRO: An Adaptive Low Mach Number Hydrodynamics…

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We describe a grid-based numerical method for 3D hydrodynamic cosmological simulations which is adaptive in space and time and combines the best features of higher order--accurate Godunov schemes for Eulerian hydrodynamics with adaptive…

Astrophysics · Physics 2016-01-27 Michael L. Norman , Greg L. Bryan

I provide a pedagogic review of adaptive mesh refinement (AMR) radiation hydrodynamics (RHD) methods and codes used in simulations of star formation, at a level suitable for researchers who are not computational experts. I begin with a…

Instrumentation and Methods for Astrophysics · Physics 2015-05-19 Mark R. Krumholz

Based on the Roe solver a new technique that allows to correctly represent low Mach number flows with a discretization of the compressible Euler equations was proposed in Miczek et al.: New numerical solver for flows at various mach…

We have written and tested a new general relativistic magnetohydrodynamics (GRMHD) code, capable of evolving MHD fluids in dynamical spacetimes with adaptive-mesh refinement (AMR). Our code solves the Einstein-Maxwell-MHD system of coupled…

High Energy Astrophysical Phenomena · Physics 2010-10-27 Zachariah B. Etienne , Yuk Tung Liu , Stuart L. Shapiro

We present a new numerical code, PLUTO, for the solution of hypersonic flows in 1, 2 and 3 spatial dimensions and different systems of coordinates. The code provides a multi-physics, multi-algorithm modular environment particularly oriented…

Astrophysics · Physics 2009-11-13 A. Mignone , G. Bodo , S. Massaglia , T. Matsakos , O. Tesileanu , C. Zanni , A. Ferrari

We have developed a new computer code, RAM, to solve the conservative equations of special relativistic hydrodynamics (SRHD) using adaptive mesh refinement (AMR) on parallel computers. We have implemented a characteristic-wise, finite…

Astrophysics · Physics 2009-11-11 Weiqun Zhang , Andrew I. MacFadyen

We present a new fourth-order, finite-volume hydrodynamics code named Apsara. The code employs a high-order, finite-volume method for mapped coordinates with extensions for nonlinear hyperbolic conservation laws. Apsara can handle arbitrary…

Computational Physics · Physics 2017-01-20 Annop Wongwathanarat , Hannes Grimm-Strele , Ewald Müller

We present Maestro, a self-supervised training method to unify representations learnt from speech and text modalities. Self-supervised learning from speech signals aims to learn the latent structure inherent in the signal, while…

Computation and Language · Computer Science 2022-07-05 Zhehuai Chen , Yu Zhang , Andrew Rosenberg , Bhuvana Ramabhadran , Pedro Moreno , Ankur Bapna , Heiga Zen

We develop a low Mach number formulation of the hydrodynamic equations describing transport of mass and momentum in a multispecies mixture of incompressible miscible liquids at specified temperature and pressure that generalizes our prior…

Fluid Dynamics · Physics 2015-06-23 A. Donev , A. J. Nonaka , A. K. Bhattacharjee , A. L. Garcia , J. B. Bell

Fluid dynamical simulations are often performed using cheap macroscopic models like the Euler equations. For rarefied gases under near-equilibrium conditions, however, macroscopic models are not sufficiently accurate and a simulation using…

Numerical Analysis · Mathematics 2023-05-31 Julian Koellermeier , Hannes Vandecasteele

We consider the problem of modeling high-speed flows using machine learning methods. While most prior studies focus on low-speed fluid flows in which uniform time-stepping is practical, flows approaching and exceeding the speed of sound…

Radiative transfer plays a key role in the star formation process. Due to a high computational cost, radiation-hydrodynamics simulations performed up to now have mainly been carried out in the grey approximation. In recent years,…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 Matthias González , Neil Vaytet , Benoît Commerçon , Jacques Masson

A non-hydrostatic depth-averaged model for dry granular flows is proposed, taking into account vertical acceleration. A variable friction coefficient based on the $\mu(I)$ rheology is considered. The model is obtained from an asymptotic…

The ideal MHD equations are a central model in astrophysics, and their solution relies upon stable numerical schemes. We present an implementation of a new method, which possesses excellent stability properties. Numerical tests demonstrate…

Instrumentation and Methods for Astrophysics · Physics 2011-04-28 Knut Waagan , Christoph Federrath , Christian Klingenberg

This paper presents an arbitrary h.o. accurate ADER DG method on space-time adaptive meshes (AMR) for the solution of two important families of non-linear time dependent PDE for compr. dissipative flows: the compr. Navier-Stokes equations…

Numerical Analysis · Mathematics 2021-07-22 Francesco Fambri , Michael Dumbser , Olindo Zanotti

This paper introduces the MAESTRO workflow, that enables the coupling of the PORTALS framework [P. Rodriguez-Fernandez et al, Nucl. Fusion 2024] with external solvers for the plasma equilibrium, pedestal physics, divertor constraints and…

We present the methodology and performance of the new Lagrangian hydrodynamics code MAGMA2, a Smoothed Particle Hydrodynamics code that benefits from a number of non-standard enhancements. By default it uses high-order smoothing kernels and…

Instrumentation and Methods for Astrophysics · Physics 2020-09-02 Stephan Rosswog

Compound LLM training workloads-such as knowledge distillation and multimodal LLM (MLLM) training-are gaining prominence. These typically comprise heterogeneous components differing in parameter scale, execution mode (forward-only or full…

We describe the development of a flux-limited gray radiation solver for the compressible astrophysics code, CASTRO. CASTRO uses an Eulerian grid with block-structured adaptive mesh refinement based on a nested hierarchy of…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 W. Zhang , L. Howell , A. Almgren , A. Burrows , J. Bell

Context. Recent, nonlinear simulations of wave generation and propagation in full-star models have been carried out in the anelastic approximation using spectral methods. Although it makes long time steps possible, this approach excludes…

Solar and Stellar Astrophysics · Physics 2020-09-15 L. Horst , P. V. F. Edelmann , R. Andrassy , F. K. Roepke , D. M. Bowman , C. Aerts , R. P. Ratnasingam