The Flow-field Optimization of Vacuum Precision Seed-metering Device with Synchronous Plate and Chamber Based on CFD

Abstract. Fast airflow velocity brings high filling rate for vacuum precision seed meters. A simulation experiment analysis had been done based on the turbulence model computational fluid dynamics (CFD) in order to optimize the structure of flow field of a vacuum precision seed-metering device with synchronous plate and chamber. The experiment was designed into orthogonal test of three factors and three levels. The distance between the cells and the back wall of the chamber, the bottom angle of the chamber and the cells angle were concerned in this simulation test. Gas velocity at the outside of hole was set as evaluating indicator. The test results showed that the cells angle and interactions between distance from the cells to the back wall of the chamber and the cells angle had a significant impact on gas velocity. The optimum combination of variance analysis for the simulation test was not the same with the optimal test results. A comparative trial was carried out to elect the optimal combination. Results of the trial indicated that the best structural parameters were 16mm, 16°and 0°respectively. And the qualified index, missing index and multiple index of the optimized metering device were 97%, 1.83%, and 1.17%, respectively at the speed of 8km/h.