标题： 聚集云的水动力学：尾流、存活、凝结和气化 显示英文标题

标题： Hydrodynamics of Clustered Clouds: Drafting, Survival, Condensation, and Ablation

摘要： 对于For等人，他们对麦哲伦流（MS）云进行了目录编目，认为麦哲伦流中存在显著的大尺度湍流。 此处我们进行了一系列FLASH模拟，以模拟云之间相互作用的流体动力学效应。 模拟套件包括一系列不同的云间距和密度。 环境条件类似于围绕麦哲伦流的环境，但也与星系际介质和星系晕介质相关。 展示了十个模拟，其中八个模拟了聚集的云，两个模拟了孤立的云。 孤立的云作为与多云模拟比较的对照组。 我们发现，如果云最初彼此靠近，流体动力学的拖曳作用会帮助后面的云追上前面的云并混合在一起。 我们测量了由于拖曳引起的加速度，并发现低密度云在低密度环境中由于拖曳而经历的加速度比它们的高密度同类更大。 我们发现云的聚集也增加了周围物质的凝结并影响了寿命。 我们使用单组分方法和多组分分解方法分析了云的速度弥散度。 我们发现第二个云的存在在某些时间会增加后面云后的速度弥散度。 我们发现模拟中由于气体运动引起的速度弥散度明显小于For等人观测到的实际弥散度，这表明在麦哲伦流中热成分必须占主导地位。 显示英文摘要

摘要： For et al., who catalogued Magellanic Stream (MS) clouds, suggested that there is substantial large-scale turbulence in the MS. Here we follow up with a series of FLASH simulations that model the hydrodynamic effects that clouds have on each other. The suite of simulations includes a range of cloud separation distances and densities. The ambient conditions are similar to those surrounding the MS but also relevant to the circumgalactic medium and intergalactic medium. Ten simulations are presented, eight of which model clustered clouds and two of which model isolated clouds. The isolated clouds are used as controls for comparison with the multicloud simulations. We find that if the clouds are initially near each other, then hydrodynamical drafting helps the trailing cloud to catch the leading cloud and mix together. We present the measured acceleration due to drafting and find that lower-density clouds in lower-density environments experience more acceleration due to drafting than their denser cohorts. We find that the clustering of clouds also increases the condensation of ambient material and affects longevity. We analyze the velocity dispersion of the clouds using a single component method and a multicomponent decomposition method. We find that the presence of a second cloud increases the velocity dispersion behind the trailing cloud at some times. We find that the velocity dispersion due to gas motion in our simulations is significantly less than the actual dispersion observed by For et al., indicating that the thermal component must dominate in the MS.