Abstract:  With regards to the problems of low mechanization level coupled with mismatch between machine type and agronomy that face the seeding of Brassica napus, an airabsorbing type precision seeder for Brassica napus was designed. The structure and working principle of seed metering device were expounded first; then the main parameters of the seeder were determined through theoretical calculation; third, the internal flow field distribution of seed metering device was analyzed in virtue of computational fluid dynamics (CFD) method and FLUENT software and both the cloud diagram of internal pressure distribution and air velocity vector of seed metering device were finally obtained, which verifies the design of seed suction, seed carrying and seed metering air field. Finally, the average qualified rate, missed rate, and multiplied rate of the seed metering apparatus were determined using a bench test whereby the values were found to be 93.18%, 2.34%, and 4.48%, respectively. It was verified through the test that the device stands out in seed metering and could satisfy the requirements of precision sowing of Brassica napus.

Key words: Brassica Chinensis, air suction seed metering device, precision seeding, computational fluid dynamics

摘要： 针对小青菜播种环节存在的精密排种与农艺匹配不够、机械化水平较低的问题，设计一款气吸式小青菜精密排种器。首先，对排种器结构及工作原理进行阐释；随后，通过理论计算确定排种器的主要参数；其次，使用计算流体力学方法（CFD），借助FLUENT软件分析排种器内部流场分布，得到排种器内部压力分布云图、气流速度矢量云图，验证吸种、携种及排种气流场设计；最后，进行台架验证试验。设计的气吸式小青菜精密排种器的平均合格率、平均漏播率、平均重播率分别为93.18%、2.34%、4.48%。试验验证了排种器具有良好的排种性能，满足小青菜精密播种要求。

关键词: 小青菜, 气吸式排种器, 精密播种, 计算流体力学