论文标题
灰尘骨料的碰撞生长效率及其对颗粒滚动摩擦强度的独立性
Collisional growth efficiency of dust aggregates and its independence of the strength of interparticle rolling friction
论文作者
论文摘要
粉尘聚集体的成对碰撞生长是量子体大小的晶粒是行星形成的第一步，因此了解灰尘骨料的碰撞行为至关重要。众所周知，主要的能量耗散机制是接触颗粒之间的切向摩擦，即滚动，滑动和扭曲。但是，滚动摩擦的强度存在很大的不确定性，并且对碰撞生长条件对滚动摩擦强度的依赖性很差。在这里，我们对具有各种碰撞速度和影响参数的两个等质多孔聚集体之间的碰撞进行了数值模拟，我们还系统地改变了滚动摩擦的强度。我们发现，粉尘聚集体碎片的碰撞速度的阈值几乎与滚动摩擦的强度无关。这是因为即使滚动摩擦的强度变化，切向摩擦的能量耗散总量几乎是恒定的。
The pairwise collisional growth of dust aggregates consisting submicron-sized grains is the first step of the planet formation, and understanding the collisional behavior of dust aggregates is therefore essential. It is known that the main energy dissipation mechanisms are the tangential frictions between particles in contact, namely, rolling, sliding, and twisting. However, there is a large uncertainty for the strength of rolling friction, and the dependence of the collisional growth condition on the strength of rolling friction was poorly understood. Here we performed numerical simulations of collisions between two equal-mass porous aggregates with various collision velocities and impact parameters, and we also changed the strength of rolling friction systematically. We found that the threshold of the collision velocity for the fragmentation of dust aggregates is nearly independent of the strength of rolling friction. This is because the total amount of the energy dissipation by the tangential frictions is nearly constant even though the strength of rolling friction is varied.
