Airflow distribution law of multi-branch pipe of pneumatic rice direct seeder based on dimensional analysis  

作　　者：Wei Qin Zaiman Wang Minghua Zhang Siyu He Xuguo Wang Youcong Jiang Zishun Huang Ying Zang 

机构地区：[1]Guangdong Laboratory for Lingnan Modern Agriculture,College of Engineering,South China Agricultural University,Guangzhou510642,China [2]Key Laboratory of Key Technology on Agricultural Machine and Equipment(South China Agricultural University),Ministry of Education,Guangzhou 510642,China [3]Guangdong Provincial Key Laboratory of Agricultural Artificial Intelligence(GDKL-AAI),Guangzhou 510642,China [4]Huangpu Innovation Research Institute of SCAU,Guangzhou 510715,China [5]Maoming Branch,Guangdong Laboratory for Modern Agriculture,Maoming 525000,Guangdong,China

出　　处：《International Journal of Agricultural and Biological Engineering》2023年第1期111-127,共17页国际农业与生物工程学报（英文）

基　　金：supported by the National Natural Science Foundation of China(Grant No.52175228);the earmarked fund for the National Key Research and Development program of China(Grant No.2021YFD2000403);the scientific research fund for the Guangdong Laboratory for Lingnan Modern Agriculture(Grant No.NZ2021039);the earmarked fund for CARS-01;the earmarked fund for the Guangdong Province Key Field Research and Development Program(Grant No.2020B020210007).

摘　　要：In order to investigate the flow characteristics and distribution law of airflow in multi-branch pipe of pneumatic rice precision direct seeder and obtain the mathematical model between airflow parameters and pipe geometry structure.In this study,the airflow flow law of the multi-branch pipeline of the pneumatic system was studied,the mechanism of airflow flow in the multi-branch pipe was analyzed,and it was clarified that the main factors affecting the airflow flow in the pipe,namely,air density,air dynamic viscosity,the total flow rate of the inlet branch pipe,the length of the closed end of the header,the inner diameter of the outlet branch pipe,and the outlet branch pipe spacing.Numerical simulations were carried out using Fluent simulation software to elucidate the cause of multi-branch pipes of uneven distribution of airflow in multi-branch pipes,the empirical equation among these factors and the flow velocity of the outlet branch pipe are established by dimensional analysis method.The bench test results show that the established empirical equations are applicable in the following ranges:0.018 m3/s≤Q≤0.054 m3/s,0.045 m≤d≤0.05 m,0.075 m≤L≤0.125 m,0.7 m≤Y 1≤0.875 m(0.5 m≤Y 2≤0.75 m,0.36 m≤Y 3≤0.45 m),the prediction accuracy can be controlled within 10%of the empirical formula,which can provide a reference for the prediction and optimization design of outlet velocity of the multi-branch pipe.

关 键 词：pneumatic system multi-branch pipe axial momentum conservation FLUENT dimensional analysis 

分 类 号：S223.2[农业科学—农业机械化工程]