中文摘要：

为提高自动卸煤车的卸煤效率,需要对煤粉在车内的流动特性及相应的卸煤时间进行深入研究.采用离散元方法对自动卸煤车的卸煤过程进行了数值模拟,确定了不同含水量下的卸煤时间.为确定离散元模型在煤粉流动分析中的有效性,采用煤粉在筒仓内的流动试验进行了模型检验和计算参数的确定.在此基础上对自动卸煤车内煤粉的流动过程进行了离散元分析,讨论了含水量对卸煤时间的影响.计算结果表明：当含水量相对较低时,受颗粒间液桥力的影响,卸煤时间随含水量的增加而增加;当含水量超过临界值后,颗粒间液桥断裂,颗粒间水分润滑减小了摩擦力,卸煤时间随含水量的增加而减小.

英文摘要：

To improve the discharging efficiency of coal hopper wagon,the flow characteristics of coal powders in wagon and the corresponding discharging time need to be investigated comprehensively. The discrete element method（ DEM） is adopted to analyze the coal discharging characteristics and determine the corresponding discharging time of the automatic coal discharging hopper wagon under different water contents. Silo experiment is designed to validate the computational parameters in the DEM simulations and the coal discharging process in the coal hopper wagon is analyzed under different water contents,and the influence of water content on the discharging time is discussed. The results show that under low water contents,the discharging time increases with increasing water content because of the inter-particle liquid bridge force. If the water content is beyond a critical value,the discharging time decreases with the increase of water content. With the DEM analysis of coal discharging in the coal hopper wagon,the influence of water content can be revealed on flow characteristics of coal material.