In this paper, a numerical simulation is applied to statistic the particle velocity and coordination number of the surface layer under the slumping regime in a rotating drum. We find that the particle velocity distribution under different coordination numbers in the avalanche always satisfies Maxwell distribution and exponential distribution. This indicated that the distribution of coordination number is the main factor causing uneven avalanche. Furthermore, the mathematical model of particle velocity and coordination number is established, and a novel method for calculating the kinetic energy of particle system is proposed. It is observed that the maximum kinetic energy of particles in different regions during the uneven avalanche is positively correlated with the avalanche duration. These results reveal the particle flow regular in the rotating drum, which provides reference data for improving the control technology of particle material flow and the heat transfer in industry.

在本文中，应用数值模拟来统计转鼓坍落状态下表面层的粒子速度和配位数。我们发现雪崩中不同配位数下的质点速度分布始终满足麦克斯韦分布和指数分布。这说明配位数的分布是造成雪崩不均匀的主要因素。进一步建立了粒子速度和配位数的数学模型，提出了一种计算粒子系统动能的新方法。观察到不均匀雪崩过程中不同区域粒子的最大动能与雪崩持续时间呈正相关。