Authors

Abstract

To simulate the interactions between the coated fertilizer particles and the fertilizer discharging components accurately, the coated fertilizer contact parameters were calibrated using the discrete element method (DEM). Based on the angle of repose test, single-factor simulations were performed on the coefficient of restitution (COR), coefficient of static friction (COSF) and coefficient of rolling friction (CORF) between particles, and the internal relationship between the level change of each factor and the static angle of repose (SAOR) was determined. The CCD test was used to calibrate the contact parameters between particles. When the COR, COSF and CORF between particles are 0.625, 0.175, and 0.037, respectively, the simulation value of SAOR is 24.173°, and the relative error from the real value is 1.230%, which indicates that the calibrated fertilizer particle contact parameters are accurate and reliable.

Abstract in Chinese

为准确模拟包膜肥料颗粒与排肥部件之间的相互作用，采用离散元法校准了包膜肥料颗粒的接触参数。通过跌落试验、斜板滑动试验和斜板滚动试验测得肥料颗粒与ABS间的碰撞恢复系数、静摩擦系数和滚动摩擦系数分别为0.47、0.42和0.095；基于休止角试验分别对颗粒间碰撞恢复系数、静摩擦系数和滚动摩擦系数进行单因素仿真，确定各因素水平变化与堆积角的内在联系。采用CCD试验标定颗粒间接触参数，对试验数据进行多元二次回归拟合，建立肥料颗粒堆积角与颗粒间接触参数的回归模型并进行最优参数求解，得到颗粒间碰撞恢复系数、静摩擦系数和滚动摩擦系数分别为0.625、0.175和0.037时，堆积角仿真值为24.173°，与真实值相对误差为1.230%，表明标定所得肥料颗粒接触参数准确可靠。