Abstract:In order to solve the problem of large amount of DEM-CFD calculation, the Fluent simulation was firstly used and threefactor threelevel orthogonal test of the position of the air inlet was designed. The mean of pressure in seed filling area holes, mean of pressure in self cleared area holes, mean of pressure in clearing seed area and pressure of other holes were taken. The mean value was the evaluation index, the range and variance analysis were carried out to determine the optimum inlet location parameters. Secondly, the Bonding model of corn grain adhesive particles was established. The structure grid of the airways flow field was divided and the relevant parameters were set up to realize the DEM-CFD gas solid coupling simulation of corn gas suction seed metering device. The pressure of the plate holes was extracted from the flow field when the corn seeds adsorbed. It was concluded that the pressure changes in each region were stable, and the pressure ranges from large to small was filling area, self cleaning area, clear seed area, seed carrying area and seed unloading area. Through theoretical calculation, the minimum pressure of adsorption was obtained, which was compared with the results obtained by simulation. The results showed that the simulation results were higher than the theoretical calculation of the minimum adsorption pressure. The first generation of conventional chamber structure seed metering device and the designed seed metering device were used to test and analyze the air pressure, which verified the rationality of the selected inlet position parameters. Finally, by changing the speed of the plate, the common operating speed of the seed metering device was 8km/h, 10km/h, 12km/h and 14km/h, and the qualified index, multiple index and missing index were used to evaluate the performance of seed metering performance under different conditions by simulation test, and the comparison was carried out through the bench test. The results showed that in the simulation test, when the operation speed was not more than 14km/h and the negative pressure was 3kPa, the qualified index was not less than 89.7%, the missing index was less than 7.8% and the multiple index was less than 2.5%. In the bench test, under the same operating speed and negative pressure value, the seed spacing qualified index can reach 90.3%, the multiple index was less than 2.7%, and the missing index was less than 7%. The simulation test was close to the bench test, which verified the feasibility of the simulation.
