油麦兼用型气送式集排器匀种涡轮设计与试验

针对油麦兼用型气送式免耕播种机宽幅播种时各行排量一致性受地表坡度变化影响的问题，设计了一种利用输送气流驱动转动、安装于分配装置的匀种涡轮，分析了匀种涡轮进口工作角和出口工作角对输送气流速度的影响，确定了影响3种匀种涡轮工作特性的关键参数。应用CFD仿真中的6自由度动网格模型及台架试验，对比分析3种匀种涡轮对输送气流分布及匀种涡轮转速的影响，结果表明：进口工作角和出口工作角均为锐角的匀种涡轮可提高种子的输送及搅拌性能。选择叶片数量为4、6、8、10的匀种涡轮进行了分配装置内流场分布仿真试验，结果表明，增加匀种涡轮叶片数量可提高匀种涡轮出口处输送气流分布的稳定及均匀性。利用智能种植机械测试平台模拟田间作业不同地表坡度时，安装不同数量叶片的匀种涡轮对各行排量一致性的影响，结果表明：转速为20～50 r/min，沿播种机作业方向的前后与侧向单向组合摆动、前后与侧向往复组合摆动角相对平整地表在-5°～5°变化，叶片数量为8时，油菜及小麦各行排量一致性变异系数最小，分别为4.99%～5.82%和3.85%～4.92%;前后与侧向单向组合摆动角绝对值为5°时，叶片数量为8的匀种涡轮比无匀种涡轮排种油菜和小麦时各行排量一致性变异系数分别降低7.53、11.98个百分点，满足地表坡度变化时油菜及小麦的排种要求。

Design and Test on Even Seeding Turbine of Air-assisted Centralized Metering Device for Rapeseed and Wheat

Considering the problem that the each seeding quantity consistency variability of air-assisted no-tillage planter for rapeseed and wheat is affected by the change of land slope, a prototype of even seeding turbine which was suitable for distributor device driven rotation by conveying airflow was developed. The influence law of inlet and outlet working angles of even seeding turbine on the velocity of conveying airflow were analyzed. The key parameters affecting the working characteristics of three kinds of even seeding turbine were determined. The effects of three kinds of even seeding turbine on the distribution of conveying airflow and the rotating speed of even seeding turbine were compared and analyzed by using the dynamic mesh model in CFD simulation and bench test. The simulation results showed that the even seeding turbine with acute inlet and outlet working angles could improve the transportation and mixing performance of seeds. The effect of even seeding turbine with 4, 6, 8 and 10 impellers on the airflow field distribution in the distributor device was carried out. The simulation results indicated that with the increase of the number of impeller, the stability and uniformity of the airflow distribution at the outlet of the even seeding turbine could be improved. The intelligent test platform for planting machines was used to simulate the effect of even seeding turbine with different numbers of impeller on the each seeding quantity consistency variability in field operation with different land slopes. The bench test results indicated that when the rotating speed was 20~50 r/min, the swing angle in one-way combination of the front or rear, and lateral, the reciprocating swing combination of front or rear, and lateral along the operation direction of the planter was relatively flat, the land surface was changed from -5°to 5°, and the number of impeller was 8, rapeseed and wheat had the lowest consistency variation coefficient of each seeding quantity. The consistency variation coefficient of each seeding quantity of rapeseed and wheat were 4.99%~5.82% and 3.85%~4.92%, respectively. When the swing angle in one way combination of the front or rear, and lateral was 5°, the consistency variation coefficient of each seeding quantity of even seeding turbine with 8 impellers was 7.53 and 11.98 percentage points lower than that of non impeller as seeding rapeseed and wheat. It could meet the requirements of rapeseed and wheat seeding when the land slope was changed.