Size and density sorting of dust grains in SPH simulations of protoplanetary discs – II. Fragmentation
Size and density sorting of dust grains in SPH simulations of protoplanetary discs – II. Fragmentation
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原行星盘 SPH 模拟中尘埃颗粒的尺寸和密度排序 – II。
DOI：
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发表时间：
2017
影响因子：
4.8
通讯作者：
C. Fitoussi
中科院分区：
文献类型：
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作者：
F. Pignatale;Jean;Nicolas Cuello;B. Bourdon;C. Fitoussi
颗粒生长和破碎是在原行星盘中形成大型尘埃聚集体的重要过程。使用 3D 两相（气体-灰尘）sph 代码，我们研究了时间演化盘中具有不同破碎阈值的多相灰尘的生长和破碎的综合影响。我们发现，我们的基准盘最初处于碎片状态，在几千年后转向纯增长状态。时间尺度随着圆盘和尘埃特性的变化而变化。当破碎有效时，它会在圆盘的不同区域产生与仅考虑纯生长时预测的不同的铁/硅和岩石/冰比率。在一些球粒陨石中观察到的化学分馏和铁的贫化/富集可能与前体尘埃颗粒的尺寸-密度分选和破碎特性有关。我们认为，如果必须保留其空气动力学排序，则在破碎效率不高的情况下，球粒状组分的聚集可能会发生。仅当球粒状组件具有相似的破碎特性时，它们才允许在破碎状态下进行空气动力学分选。我们发现，在内盘中，在相同的时间间隔内，与纯粹生长预测的颗粒尺寸相比，碎片灰尘会变得更大。这种反直觉的行为是由于大量灰尘堆积在破碎区域，然后当该区域过渡到纯生长状态时发生快速生长。一个重要的结果是，灰尘可以在几千年内克服径向漂移障碍。
Grain growth and fragmentation are important processes in building up large dust aggregates in protoplanetary discs. Using a 3D two-phase (gas–dust) sph code, we investigate the combined effects of growth and fragmentation of a multiphase dust with different fragmentation thresholds in a time-evolving disc. We find that our fiducial disc, initially in a fragmentation regime, moves towards a pure-growth regime in a few thousands years. Time-scales change as a function of the disc and dust properties. When fragmentation is efficient, it produces, in different zones of the disc, Fe/Si and rock/ice ratios different from those predicted when only pure growth is considered. Chemical fractionation and the depletion/enrichment in iron observed in some chondrites can be linked to the size–density sorting and fragmentation properties of precursor dusty grains. We suggest that aggregation of chondritic components could have occurred where/when fragmentation was not efficient if their aerodynamical sorting has to be preserved. Chondritic components would allow aerodynamical sorting in a fragmentation regime only if they have similar fragmentation properties. We find that, in the inner disc, and for the same interval of time, fragmenting dust can grow larger when compared to the size of grains predicted by pure growth. This counter-intuitive behaviour is due to the large amount of dust that piles up in a fragmenting zone followed by the rapid growth that occurs when this zone transitions to a pure growth regime. As an important consequence, dust can overcome the radial-drift barrier within a few thousands years.
影响因子：
4.8
作者：
Deckers, J.;Teiser, J.
通讯作者：
Teiser, J.
气体和粉尘混合物的平滑颗粒流体动力学模拟
影响因子：
4.8
作者：
Booth R
通讯作者：
Booth R
影响因子：
3.2
作者：
V. Mannings;A. Boss;S. Russell
通讯作者：
V. Mannings;A. Boss;S. Russell