摘要
针对玉米气吸式排种器高速作业下种子运动十分复杂、难以进行准确分析计算的问题,采用DEM(离散元)和CFD(计算流体力学)耦合的方法,模拟了气吸式排种器工作过程,分析了种子受到的曳力和运动速度,得出不同种子充种能力大小依次为:小扁形、类圆形、大扁形。经过仿真分析,有针对性地选取不易吸附充种的大扁形种子,建立充种过程数学模型,优化种盘型孔凸台高度和型孔凸台角度参数。为了获得排种器的最佳性能参数,以型孔凸台角度、型孔凸台高度、种层高度为试验因素,以排种合格指数、重播指数、漏播指数为试验指标进行三因素二次旋转正交组合试验,并应用Design-Expert 8. 0. 6软件对试验数据进行多元回归分析和响应曲面分析,得到了各因素对指标影响关系。采用多目标优化方法,确定了最佳参数组合:型孔凸台角度为35. 76°,型孔凸台高度为3. 11 mm,种层高度为55. 61 mm,排种合格指数最高。此时,排种器性能指标为:合格指数91. 60%,漏播指数3. 90%,重播指数4. 50%。对优化结果进行验证试验,并与原排种器进行对比,验证结果与优化结果基本一致,且合格指数和漏播指数均优于原排种器,满足玉米精密播种的要求。
The seeds movement under the high-speed operation condition of corn air suction metering device is very complicate, and it is difficult to carry out accurate analysis and calculation. The discrete element (DEM) and computational fluid dynamics (CFD) coupling method was used to accurately simulate the working process of air suction metering device, the bonding model of Zhengdan 958 corn seed cohesive particles was established, the airway structured grid was divided, and the related parameters were set up. The coupling simulation of EDEM and CFD was realized. Through simulation, the working process of the air suction metering device was accurately simulated, and the drag force and movement speed of the seeds were accurately analyzed. It was concluded that the seed filling ability of different seeds from big to small was as follows: small flat shape, round shape and big flat shape. In order to improve the operation quality of seed metering device and ensure the adaptability of seed metering device to seeds, the optimum design of seed plate structure for big flat shape was studied. The mathematical model of filling process was established to optimize the height of the plate type hole embossment and the angle parameter of the type hole embossment. Because of the complex movement caused by the interaction between seed populations and the interaction between seed populations and metering devices when the metering plate was rotated, further analysis and determination of the optimum angle were needed. In order to obtain the best performance parameters of the seed metering device, the angle of the type hole embossment, the height of the type hole embossment and the height of the seed layer were taken as the test factors, and the three factors of the seeding qualified index, multiple index and missing index were used as test indicators. Performing a three-factor quadratic rotation orthogonal combination test, the Design-Expert 8.0.6 software was used to analyze the test data by multiple regression analysis and response surf
作者
丁力
杨丽
张东兴
崔涛
高筱钧
DING Li;YANG Li;ZHANG Dongxing;CUI Tao;GAO Xiaojun(College of Engineering,China Agricultural University,Beijing 100083,China;Key Laboratory of Soil Machine Plant System Technology,Ministry of Agriculture and Rural Affairs,Beijing 100083,China)
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2019年第5期50-60,共11页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家重点研发计划项目(2017YFD0700703)
国家自然科学基金项目(51575515)
国家玉米产业技术体系建设项目(CARS-02)
关键词
玉米
气吸式排种器
离散元
计算流体力学
响应面法
回归分析
corn
air suction seed metering device
discrete element
computational fluid dynamics
response surface method
regression analysis
