论文标题
粘性耗散对碰撞生长和灰尘骨料破碎的影响
Impacts of viscous dissipation on collisional growth and fragmentation of dust aggregates
论文作者
论文摘要
了解由亚微米大小的晶粒组成的灰尘骨料的碰撞行为对于揭示在原星盘中如何形成的行星。众所周知，个体尘埃的碰撞行为在很大程度上取决于粘性耗散力的强度。但是，粘性耗散对灰尘骨料碰撞行为的影响尚未详细研究，尤其是对于倾斜碰撞的情况。在这里，我们研究了粘性耗散对灰尘骨料碰撞行为的影响。我们对具有各种碰撞速度和影响参数的两个相等质量灰尘聚集体之间的碰撞进行了数值模拟。我们还系统地改变了粘性耗散力的强度。我们发现，当我们考虑倾斜碰撞时，灰尘聚集体碎片的阈值碰撞速度几乎不取决于粘性耗散力的强度。相反，当考虑粘性耗散力时，碎片的尺寸分布显着变化。我们获得了用于强大耗散情况的片段的尺寸分布的经验拟合公式，这对于研究原球磁盘中尘埃骨料的大小和空间分布的演变非常有用。
Understanding the collisional behavior of dust aggregates consisting of submicron-sized grains is essential to unveiling how planetesimals formed in protoplanetary disks. It is known that the collisional behavior of individual dust particles strongly depends on the strength of viscous dissipation force; however, impacts of viscous dissipation on the collisional behavior of dust aggregates have not been studied in detail, especially for the cases of oblique collisions. Here we investigated the impacts of viscous dissipation on the collisional behavior of dust aggregates. We performed numerical simulations of collisions between two equal-mass dust aggregates with various collision velocities and impact parameters. We also changed the strength of viscous dissipation force systematically. We found that the threshold collision velocity for the fragmentation of dust aggregates barely depends on the strength of viscous dissipation force when we consider oblique collisions. In contrast, the size distribution of fragments changes significantly when the viscous dissipation force is considered. We obtained the empirical fitting formulae for the size distribution of fragments for the case of strong dissipation, which would be useful to study the evolution of size and spatial distributions of dust aggregates in protoplanetary disks.
