[目的]解决水稻机械直播速度慢、效率低的问题.[方法]采用气流分配式排种器进行水稻直播,优化设计一种由R可调节的喇叭口式内腔与α可变的分流密封盖组成的α-R式气流分配式排种器,利用EDEM-Fluent耦合模块,对气流分配排种过程进行数值模拟;并进行排种性能台架验证试验.[结果]仿真结果显示,α-R组合式分配器中水稻颗粒最高运动速度为5.416 m·s-1,且旋涡滞种区域面积也低于传统结构,水稻颗粒在分配器中排出顺畅;R=180 mm、α=20°时,排种均匀性变异系数为24.56%,各行一致性变异系数为3.79%,总排量稳定性变异系数为1.23%,3项指标均为最优.采用3D打印的分配器进行台架试验,结果显示该排种器排种均匀性变异系数为29.17%~30.86%,各行一致性变异系数为4.13%~4.33%,总排量稳定性变异系数为1.4%~1.7%,满足水稻机械直播要求.[结论]多次试验结果稳定,与仿真结果较为接近,说明本次设计的气流分配式排种器满足要求,也表明利用EDEM-Fluent耦合模拟的正确性与可行性.%[Objective] To solve the problems of slow speed and inefficiency in mechanical seeding of rice.[Method]Rice was directly seeded using the air distribution seed-metering device.An α-R air distribution seed-metering device was designed and optimized.It consisted a bell type lumen with adjustable R and a shunt seal cap with adjustable α.Numerical simulations of air distribution and metering process were performed by using EDEM-Fluent coupling module, and the bench test on seeding performance was carried out.[Result]The simulation results showed that the highest velocity of rice particles in the combined α-R distributor was 5.416 m·s-1.The area of vortex stagnation was smaller than that of the traditional structure.Rice particles were discharged smoothly from the dispenser.When R=180 mm and α=20°, the variation coefficient of uniformity was 24.56%, the variation coefficient of consistency among rows was 3.79%, the variation coefficient of total displacement stability was 1.23%, and the three indicators were all the optimum values.Bench test was carried out using distributors printed by 3D printer and the results showed that the variation coefficient of uniformity for the seed-metering device was 29.17%-30.86%, the variation coefficient of consistency among rows was 4.13%-4.33% and the variation coefficient of total displacement stability was 1.4%-1.7%, which met the requirements of mechanical seeding of rice.[Conclusion]The results from multiple tests are stable and close to the simulation results.The designed air distribution seed-metering device can meet practical requirements, suggesting that using the EDEM-Fluent coupling simulation is correct and feasible.
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