发表机构
Universität Heidelberg; Università degli Studi di Torino; Iowa State University; University of Nevada, Las Vegas; Max-Planck-Institut für Astronomie（海德堡大学; 都灵大学; 爱荷华州立大学; 内华达大学拉斯维加斯分校; 马克斯·普朗克天文研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究在全局盘模型中比较了粒子与流体方法模拟流不稳定性，发现流体方法（FARGO3D与PLUTO）收敛，而粒子方法需更高分辨率或更多粒子，并指出更精确的黎曼求解器可改善结果。
AI 中文摘要
识别与行星形成相关的过程仍是一项主要任务。目前已识别出可以捕获尘埃、阻止其向内迁移的机制。一种被称为流不稳定性（streaming instability）的特殊流体动力学不稳定性备受关注，因为它可能负责形成第一批星子（planetesimals）得以形成的尘埃团块。我们旨在使用两种基本方法，在更真实的全局盘模型中比较非线性流不稳定性模拟的结果。这些结果将不会用于识别或区分例如流体模拟中的数值扩散或粒子流交叉的可能性等效应，而是将使我们能够确定拉格朗日粒子方法是否最适合用于流不稳定性的数值研究。方法：我们使用两个代码FARGO3D（尘埃流体）和PLUTO（流体、粒子）进行二维、轴对称、全局且等温的流体动力学模拟，以研究尘埃标高、中平面尘埃与气体比、最大尘埃密度的时间演化，并研究速度分布和涡度。对于PLUTO粒子模拟，我们还研究了气体黎曼求解器和空间重构阶数的影响。我们进行分辨率研究，最高达每个气体标高5120个单元，结果表明PLUTO流体与FARGO3D之间收敛。两者均产生由小尺度、尘埃贫乏的空洞主导的高斯轮廓。使用PLUTO的粒子模拟尚未收敛，因为一个瞬态的中平面尘埃成分持续存在，表明需要更高的分辨率或更多的粒子。使用更精确的黎曼求解器或更高阶的空间重构方案有助于使尘埃密度轮廓更接近收敛结构。
英文摘要
Identifying the process relevant to planet formation is still a major task. Mechanisms have been identified that can trap dust, preventing it from migrating inwards. A particular hydrodynamic instability, known as the streaming instability, is of high interest because it may be responsible for the formation of dust clumps from which the first planetesimals form. We aim to compare the outcome of non-linear streaming instability simulations using both fundamental approaches in a more realistic global disk model. The results will not be used to identify or disentangle the effect of, e.g., numerical diffusion in fluid simulations or the possibility of having crossing particle streams. Instead, they will enable us to determine whether the Lagrangian particle approach is the most suitable for numerical studies of the streaming instability. Methods: We perform 2D, axisymmetric, global, and isothermal hydrodynamic simulations using the two codes FARGO3D (dust fluid) and PLUTO (fluid, particles) to investigate the temporal evolution of dust scale height, midplane dust-to-gas ratio, and maximum dust density as well as to study velocity distributions and vorticities. For PLUTO particle simulations, we also investigate the influence of the gas Riemann solver and spatial reconstruction orders. Our results from a resolution study up to 5120 cells per gas scale height indicate convergence between PLUTO fluid and FARGO3D. Both yield a Gaussian profile dominated by small-scale, dust-depleted voids. Particle simulations with PLUTO have not yet converged, as a transient midplane dust component persists, indicating the need for even higher resolution or more particles. Using a more accurate Riemann solver or a higher-order spatial reconstruction scheme helps to bring the dust density profile closer to the converged structure.
Comments22 pages, 24 figures
