Authors

Abstract

To address parameter optimization and fertilization uniformity of a fluted-wheel fertilizer metering device for granular organic fertilizer, a 3D-scanned fertilizer model was constructed, and an EDEM fertilization simulation model was established. The Poisson’s ratio and elastic modulus of the fertilizer were determined using a texture analyzer. Drop tests were conducted to determine the coefficients of restitution between fertilizer particles and between the fertilizer and PA, PC, and PLA. Inclined-plane rolling tests were conducted to determine the rolling friction coefficients between the fertilizer and PA, PC, and PLA. A cylinder-lifting test for measuring the angle of repose, combined with EDEM simulations and a Design-Expert experimental design, was used to determine the static and rolling friction coefficients between fertilizer particles, as well as the static friction coefficients between the fertilizer and PA, PC, and PLA. By combining the discrete element method (DEM) with response surface methodology, the effects of the parameters on fertilization uniformity were ranked as follows: fluted-wheel inscribed-circle diameter > fluted-wheel lead angle > number of grooves; fertilizer-metering shaft rotational speed > fertilizer-discharge flap angle > effective working length of the fluted wheel. The optimal parameter combination was determined to be a fluted-wheel inscribed-circle diameter of 37 mm, 7 grooves, a fluted-wheel lead angle of 63°, an effective working length of the fluted wheel of 31 mm, a fertilizer-metering shaft rotational speed of 28 rpm, and a fertilizer-discharge flap angle of −1°. Soil-bin tests using 3D-printed fluted wheels with different structural parameters produced results that were generally consistent with the simulation results, providing a reference for the DEM-based optimization and design of fluted-wheel fertilizer metering devices.

Abstract in Chinese

针对外槽轮式排肥器施用颗粒有机肥参数优化与施肥均匀性问题，构建肥料3D扫描模型，建立施肥EDEM仿真模型。通过质构仪，获得肥料泊松比和弹性模量；通过下落试验，获得肥料与肥料、PA、PC、PLA的碰撞恢复系数；通过斜面滚动试验，获得肥料与PA、PC、PLA的滚动摩擦系数；通过休止角圆筒提升试验、EDEM仿真，结合Design-Expert试验设计，测定肥料与肥料静摩擦系数、滚动摩擦系数，肥料与PA、PC、PLA的静摩擦系数。结合离散元法（DEM）与响应面法，获得参数对施肥均匀性的影响排序分别为：槽轮内接圆直径>槽轮升角>凹槽个数；排肥轴转速>排肥舌角度>槽轮有效工作长度。最优参数组合是：槽轮内接圆直径为37mm，凹槽数量为7，槽轮升角为63°，槽轮有效工作长度为31mm，排肥轴转速为28RPM，排肥舌角度为-1°。采用3D打印不同结构参数槽轮，土槽试验结果与仿真基本一致，为排肥器离散元优化设计提供参考