Abstract Residence time distribution (RTD) of barley grains with elliptical shape were investigated in wedge-shaped and flat-bottom silos using the discrete element method (DEM) and experiments. The velocity distribution of particles were captured using particle image velocimetry during silo discharge. Multi-sphere method (a combination of three spheres) was used to simulate the granular flow by DEM. The model was validated using the experimental results relative to distributions of lateral and axial components of particle velocity. The obtained RTDs were interpreted using the flow pattern of particles. In the flat-bottom silo, the regions on the top of the outlet showed the shortest residence times. The residence times of particles increased as the height increased above the outlet, in the center of the silos. In the regions close to the walls (outside of the outlet region) of the flat-bottom silo, residence time of particles decreased with increasing height. On the other hand, in the wedge-shaped silo, particles in the outlet zone showed the shortest residence times while the particles located on the inclined silo wall out of the outlet zone have the longest residence times. Effects of wedge angle and initial filled height were also studied and discussed on the residence time distribution.

中文翻译：

---

筒仓中非球形颗粒的速度分布和停留时间分布的实验和 DEM 研究

摘要 使用离散元法（DEM）和实验研究了椭圆形大麦粒在楔形和平底筒仓中的停留时间分布（RTD）。在筒仓排放期间使用粒子图像测速仪捕获粒子的速度分布。多球法（三个球体的组合）用于通过 DEM 模拟颗粒流。该模型使用与粒子速度的横向和轴向分量分布相关的实验结果进行了验证。使用粒子的流动模式解释获得的 RTD。在平底筒仓中，出口顶部的区域显示出最短的停留时间。颗粒的停留时间随着出口上方、筒仓中心的高度增加而增加。在靠近平底筒仓壁的区域（出口区域外），颗粒的停留时间随着高度的增加而减少。另一方面，在楔形筒仓中，出口区的颗粒停留时间最短，而位于出口区外倾斜筒仓壁上的颗粒停留时间最长。还研究和讨论了楔角和初始填充高度对停留时间分布的影响。