On Validating an Astrophysical Simulation Code

By A. Calder, B. Fryxell, Tomasz Plewa, R. Rosner, L. Jonathan Dursi, V. Gregory Weirs, Todd Dupont, H. Robey, J. Kane, B. Remington and 8 more. 2002

196 citations recorded by the source corpus.

We present a case study of validating an astrophysical simulation code. Our study focuses on validating FLASH, a parallel, adaptive-mesh hydrodynamics code for studying the compressible, reactive flows found in many astrophysical environments. We describe the astrophysics problems of interest and the challenges associated with simulating these problems. We describe methodology and discuss solutions to difficulties encountered in verification and validation. We describe verification tests regularly administered to the code, present the results of new verification tests, and outline a method for testing general equations of state. We present the results of two validation tests in which we compared simulations to experimental data. The first is of a laser-driven shock propagating through a multilayer target, a configuration subject to both Rayleigh-Taylor and Richtmyer-Meshkov instabilities. The second test is a classic Rayleigh-Taylor instability, where a heavy fluid is supported against the force of gravity by a light fluid. Our simulations of the multilayer target experiments showed good agreement with the experimental results, but our simulations of the Rayleigh-Taylor instability did not agree well with the experimental results. We discuss our findings and present results of additional simulations undertaken to further investigate the Rayleigh-Taylor instability.

Subfields: Astronomy and Astrophysics, Computational Mechanics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/03d3dda512653ff2df8c0f412b1bc37cacef5aec

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Citations in the corpus

The Piecewise Parabolic Method for Multidimensional Relativistic Fluid Dynamics (2005, background): “Thanks to their relative simplicity, one-dimensional problems are also excellent benchmarks that can be used for comparison of different algorithms and implementations (Calder et al. 2002).”
Experimental astrophysics with high power lasers and Z pinches (2004, methodology): “Detailed simulations of this experiment were carried out as part of a validation study by Calder et al. 2002, 2004 for the astrophysical code FLASH, which includes adaptive grids and other advanced features.”
Draping of Cluster Magnetic Fields over Bullets and Bubbles—Morphology and Dynamic Effects (2007, methodology): “Since we have not prescribed any smallscale dissipative physics in these simulations, these instabilities will never properly converge with increased resolutin (e.g., Calder et al. 2002) as new unstable scales are added.”
An unsplit staggered mesh scheme for multidimensional magnetohydrodynamics: a staggered dissipation-control differencing algorithm (2006, methodology): “of 600,000 lines of code and was awarded the 2000 Gordon Bell Award [22] in the Special Category for achieving 0.”
MODELING COLLAPSE AND ACCRETION IN TURBULENT GAS CLOUDS: IMPLEMENTATION AND COMPARISON OF SINK PARTICLES IN AMR AND SPH (2010, methodology): “…the ambipolar diffusion module, and with either the multigrid or the tree gravity solver. flash has been extensively tested against laboratory experiments (Calder et al. 2002) and other codes (Dimonte et al. 2004; Heitmann et al. 2005; Agertz et al. 2007; Tasker et al. 2008; Kitsionas et al. 2009).”
Supernova Simulations with Boltzmann Neutrino Transport: A Comparison of Methods (2003, background): “The gap in code validation between detached analytical test calculations and the astrophysical application can be bridged by code comparisons (Calder et al. 2002), based on the assumption that different numerical approaches are likely to show different strengths and weaknesses in simulations of…”
MODULES FOR EXPERIMENTS IN STELLAR ASTROPHYSICS (MESA) (2010, background): “V&V is a maturing discipline (e.g., Roache 1998; Calder et al. 2002), with the goal of assessing the error and uncertainty in a numerical simulation, which also includes addressing sources of error in theory, experiment, observation, and computation (Calder et al. 2004).”
A comparison between grid and particle methods on the statistics of driven, supersonic, isothermal turbulence (2010, methodology): “…respectively were usedin a mode of parallel computation, each calculation taking roughly 12, 250 and 5000 CPU-hours respectively.FLASH has been extensively tested against laboratory experiments (Calder et al. 2002)and other codes (Dimonte et al. 2004; Heitmann et al. 2005; Kitsionas et al. 2009).”
CONVECTIVE–REACTIVE PROTON–12C COMBUSTION IN SAKURAI'S OBJECT (V4334 SAGITTARII) AND IMPLICATIONS FOR THE EVOLUTION AND YIELDS FROM THE FIRST GENERATIONS OF STARS (2010, background): “It is incorporated in the community codes VH1 (Blondin & Lufkin 1993), ENZO (Bryan et al. 1995), and FLASH (Calder et al. 2002).”