A discrete element model based on super-ellipsoids was used to simulate cylindrical particle flow. The model can describe a cylindrical particle accurately provided the shape indices of the super-ellipsoids are set to appropriate values. To achieve more rapid calculations, we implemented an “oriented bounding box algorithm” (OBBA) for the initial contact detection of cylindrical particles. Several types of simulations were performed to validate the super-ellipsoid model and the contact-detection algorithm. First, the effect of shape index of the super-ellipsoids on model accuracy was investigated through three simulations: impact of a cylindrical particle on a flat wall, flow of cylindrical particles in a rotating tumbler, and segregation of cylindrical particles of different length flowing down a bounded heap. The simulation results show that the super-ellipsoids describe cylindrical particles accurately when the shape index that specifies the sharpness of the cylinder edges is sufficiently large. The efficiency of the OBBA is measured by simulations in which a box is filled with cylindrical particles and a tumbler that contains cylindrical particles is rotated. The simulation results show that the OBBA can accelerate the calculations significantly. The effect of particle shape (such as aspect ratio and shape index) on the calculation speed was obtained. The simulation of rod-like particles tended to take more calculation time than that of disk-like particles, and the simulation time increased with an increasing particle-shape index.

基于超级椭球的离散元模型被用来模拟圆柱状颗粒流。只要将超级椭圆体的形状指数设置为适当的值，该模型就可以准确地描述圆柱状颗粒。为了实现更快的计算速度，我们为圆​​柱颗粒的初始接触检测实施了“定向包围盒算法”（OBBA）。进行了几种类型的仿真，以验证超椭圆体模型和接触检测算法。首先，通过三个模拟研究了超级椭圆体的形状指数对模型精度的影响：圆柱颗粒对平面壁的影响，圆柱颗粒在旋转的转鼓中的流动以及不同长度的圆柱颗粒向下流动的偏析有限的堆。仿真结果表明，当指定圆柱边缘锐度的形状指标足够大时，超椭圆形可以准确地描述圆柱颗粒。通过模拟来测量OBBA的效率，在模拟中，一个盒子里装满了圆柱状颗粒，旋转了一个装有圆柱状颗粒的玻璃杯。仿真结果表明，OBBA可以大大加快计算速度。获得了颗粒形状（如长径比和形状指数）对计算速度的影响。棒状颗粒的模拟比盘状颗粒的计算耗费更多的时间，并且随着颗粒形状指数的增加，模拟时间也随之增加。