Simulation Analysis Of Working Process Of Air Suction Corn Precision Seed-metering Device Based On DEM-CFD Coupling Method

In this paper, air suction corn precision seed-metering device is considered as the research object. Corn seeds are divided into different types according to their different shape characteristics, and the use of alternative ways to establish a particle corn seeds spheres bond model, as the coupling simulation model. By using EDEM software and FLUENT software coupled manner to analyze the work of the seeding process simulation, and compared with bench tests to verify the validity of simulation. The main work and conclusions are as follows.(1) This paper selected six different varieties of corn seeds for the study. And they were measured its moisture content、density and other physical and mechanical parameters. Analyzing the differences between corn seeds of different varieties of shapes and sizes, and according to their different shape characteristics are divided into different types. Selecting from two varieties of six varieties for the study, by using three-dimensional laser scanner its geometric profile, and the ball particle bonding method was used to fill it. Finally, replacing the simulation model to obtain corn seeds particles by alternative.(2) To study the effect of suction seed optimum performance parameters, bench tests were carried out on the seed metering device, by using the JPS seed metering device which belongs to our laboratory. Single factor experiment of the speed and vacuum and orthogonal test were carried out respectively to PingAn 134 and ZhengDan 958 corn seeds to get the best working parameters. And bench tests were carried out on the other four varieties of corn seeds on the basis of the parameters. In order to compare the air suction metering device under the same conditions on seeding performance differences among different corn varieties.(3) The mesh of the simplified seed metering device was divided by GAMBIT software. Using sliding mesh model to solve the problem of seed metering disk rotation. Analysing of the internal flow field of the simplified seed metering device in FLUENT software, by changing the rotation speed, vacuum degree and the number of the type of disc.(4) The simulation model corn seeds previously established in the EDEM in the simulation parameters were calibrated, including coefficient of restitution、dynamic friction coefficient and static friction coefficient. Through the EDEM software and FLUENT software coupling, simulation analysis was carried out for the air suction metering device in working process, and compared with the bench test in the third chapter, in order to verify the feasibility of the simulation, and provide the basis for the optimal design of the seed metering device.