Particle splitting in smoothed particle hydrodynamics based on Voronoi diagram
Particle splitting in smoothed particle hydrodynamics based on Voronoi diagram
复制标题
基于 Voronoi 图的平滑粒子流体动力学中的粒子分裂
DOI：
10.1093/mnras/stv1227
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发表时间：
2015
影响因子：
4.8
通讯作者：
Naoki
中科院分区：
文献类型：
--
作者：
Chiaki;Gen; Yoshida;Naoki
提出了一种光滑粒子流体力学模拟中粒子分裂的新方法。我们的方法利用给定粒子集的Voronoi图来确定细子粒子的位置。我们进行了几个测试模拟来比较我们的方法与传统的分裂方法，其中子粒子在局部平滑长度上各向同性地放置。结果表明，与传统方法相比，我们的方法将分裂后的密度偏差降低了约2倍。如果子粒子是各向同性分布的，分裂会使各向异性密度结构变得平滑，但我们的方案允许子粒子以其母体平均分离的长度尺度追踪原始密度分布。我们将粒子分裂应用于原始气体云坍缩的模拟。热演化精确地跟踪到氢数密度为1012cm−3。多步粒子分裂后的有效质量分辨率为~ 10−4M⊙，可以很好地分辨原恒星盘结构。我们得出结论，该方法为模拟星际气体的演化和恒星的形成提供了一种有效的方法。
We present a novel method for particle splitting in smoothed particle hydrodynamics simulations. Our method utilizes the Voronoi diagram for a given particle set to determine the position of fine daughter particles. We perform several test simulations to compare our method with a conventional splitting method in which the daughter particles are placed isotropically over the local smoothing length. We show that, with our method, the density deviation after splitting is reduced by a factor of about 2 compared with the conventional method. Splitting would smooth out the anisotropic density structure if the daughters are distributed isotropically, but our scheme allows the daughter particles to trace the original density distribution with length-scales of the mean separation of their parent. We apply the particle splitting to simulations of the primordial gas cloud collapse. The thermal evolution is accurately followed to the hydrogen number density of 1012cm−3. With the effective mass resolution of ∼10−4M⊙after the multistep particle splitting, the protostellar disc structure is well resolved. We conclude that the method offers an efficient way to simulate the evolution of an interstellar gas and the formation of stars.