EMMA: an adaptive mesh refinement cosmological simulation code with radiative transfer
EMMA: an adaptive mesh refinement cosmological simulation code with radiative transfer
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EMMA：具有辐射传递的自适应网格细化宇宙学模拟代码
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
P. Ocvirk
中科院分区：
文献类型：
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作者：
D. Aubert;N. Deparis;P. Ocvirk
EMMA是一个宇宙学模拟程序，旨在研究再电离时期。它同时处理无碰撞和气体动力学，以及辐射传输物理学，使用基于M1近似的矩描述。场量在自适应3D网格上存储和计算，并且空间分辨率可以基于物理激励标准动态修改。物理过程可以在所有空间和时间尺度上耦合。我们还引入了一个新的和可选的近似来处理辐射：光在非细化网格的分辨率下传输，并且只有在动力学完全更新之后，而热化学过程仍然在细化元素上跟踪。这种近似减少了辐射物理处理引起的管理费用。EMMA提出并通过了一套标准测试，为今后在再电离时代的研究中使用提供了验证。该代码是并行的，能够使用图形处理单元（GPU）来加速流体力学和辐射传输计算。根据优化和用于生成CPU参考的编译器，可以获得x3.9和x16.9之间的全局GPU加速因子。目前，矢量化和传输操作阻碍了GPU性能的提高，我们预计未来的优化和硬件发展将带来更大的加速。
EMMA is a cosmological simulation code aimed at investigating the reionization epoch. It handles simultaneously collisionless and gas dynamics, as well as radiative transfer physics using a moment-based description with the M1 approximation. Field quantities are stored and computed on an adaptive 3D mesh and the spatial resolution can be dynamically modified based on physically-motivated criteria. Physical processes can be coupled at all spatial and temporal scales. We also introduce a new and optional approximation to handle radiation : the light is transported at the resolution of the non-refined grid and only once the dynamics have been fully updated, whereas thermo-chemical processes are still tracked on the refined elements. Such an approximation reduces the overheads induced by the treatment of radiation physics. A suite of standard tests are presented and passed by EMMA, providing a validation for its future use in studies of the reionization epoch. The code is parallel and is able to use graphics processing units (GPUs) to accelerate hydrodynamics and radiative transfer calculations. Depending on the optimizations and the compilers used to generate the CPU reference, global GPU acceleration factors between x3.9 and x16.9 can be obtained. Vectorization and transfer operations currently prevent better GPU performances and we expect that future optimizations and hardware evolution will lead to greater accelerations.