基于离散元法的煤颗粒摩擦系数标定研究
Research on Calibration of Coal Particle Friction Coefficient Based on Discrete Element Method

为了简单且精确地标定煤颗粒摩擦系数的数值，提出了一种仿真与实验相结合的测定堆积角方法来推导煤颗粒摩擦系数。在分析煤颗粒堆积角与摩擦系数之间的函数关系后，建立二阶预测模型，以此逆推煤颗粒摩擦系数。用基于离散元法来创建煤颗粒模型进行大量堆积仿真试验，用MATLAB对最终堆积图片处理，提取堆积外轮廓曲线并进行线性拟合，计算堆积角度，最后将堆积角带入数学模型中逆推摩擦系数。再用相同的装置与方法进行煤颗粒堆积实验，验证仿真的可行性与结果的准确性。结果表明：通过煤颗粒堆积角推导煤颗粒摩擦系数是合理的、可行的，采用仿真试验和真实实验相结合的方法能使得标定过程简单且求解出的各项摩擦系数结果精确。
In order to calibrate the friction coefficient of coal particles simply and accurately, a method of measuring the stacking angle combining simulation with experiment is proposed to deduce the friction coefficient of coal particles. Based on the analysis of the functional relationship between the stacking angle of coal particles and the friction coefficient, a second-order prediction model is established to deduce the friction coefficient of coal particles. The coal particle model is created based on the discrete element method to carry out a large number of stacking simulation experiments. The final stacking image is processed with MATLAB, and the stacking contour curve is extracted and linearly fitted to calculate the stacking angle. Finally, the stacking angle is brought into the mathematical model to deduce the friction coefficient. Then the same device and method are used to carry out the coal particle stacking experiment to verify the feasibility of the simulation and the accuracy of the results. The results show that it is reasonable and feasible to deduce the friction coefficient of coal particles from the stacking angle of coal particles, and the combination of simulation test and real experiment can make the calibration process simple and the calculated friction coefficient results accurate.