An adaptive hierarchical particle-mesh code with isolated boundary conditions
An adaptive hierarchical particle-mesh code with isolated boundary conditions
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DOI：
10.1086/303949
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发表时间：
1997-05-01
影响因子：
4.9
通讯作者：
Wasserman, I
中科院分区：
文献类型：
--
作者：
Gelato, S;Chernoff, DF;Wasserman, I
本文描述了一种新的、完全自适应的粒子多重网格(PM2)数值模拟程序，该程序主要是为宇宙学应用而开发的。该程序集成了一组粒子的运动方程，这些粒子受到相互引力相互作用和可选的任意外场的影响。粒子之间的相互作用使用在每个积分步骤重新构建的嵌套网格的层次结构来计算，以提高高密度感兴趣区域的空间分辨率。由于该代码的目标是模拟相对较小的空间(不比一组星系大多少)，并独立控制外部潮汐场，因此在支持顶部网格级别的孤立边界条件方面做出了重大努力。这使得我们的方法也适用于非宇宙学问题，但代价是一些复杂的问题，我们将对此进行讨论。我们指出了我们的方法与其他类似代码作者的方法之间的一些差异的影响，特别是在处理不同空间分辨率的区域之间的界面方面。我们提供了一系列测试来验证我们实现的正确性和性能。这一结论提出了在独立时间步长和粒子软化长度方面进一步改进的可能性。
This article describes a new, fully adaptive particle-multiple-mesh (PM2) numerical simulation code developed primarily for cosmological applications. The code integrates the equations of motion of a set of particles subject to their mutual gravitational interaction and to an optional, arbitrary external field. The interactions between particles are computed using a hierarchy of nested grids constructed anew at each integration step to enhance the spatial :resolution in high-density regions of interest. As the code is aimed at simulations of relatively small volumes of space (not much larger than a single group of galaxies) with independent control over the external tidal fields, significant effort has gone into supporting isolated boundary conditions at the top grid level. This makes our method also applicable to non-cosmological problems, at the cost of some complications, which we discuss. We point out the implications of some differences between our approach and those of other authors of similar codes, in particular with respect to the handling of the interface between regions of different spatial resolution. We present a selection of tests performed to verify the correctness and performance of our implementation. The conclusion suggests possible further improvements in the areas of independent time steps and particle softening lengths.