| In order to improve the cleaning performance of wheat combine harvester for wheat/maize intercropping system, we studied the motion states of the flow field and particles in the cyclone separator and investigated the optimal working parameter combination of the separator. In this study, airflow and particle interaction was analyzed by using the coupling simulation of discrete element method and computational fluid dynamics. The factors of the cleaning process simulation orthogonal experiment used were feeding speed, the outlet pressure, the cylinder height, and the lower vertebral angle. The simulation was validated in the field. The results showed that: the inner and outer vortex was formed by the movement of airflow in the separator; the short stems were sucked into suction pipe by inner vortex movement; the seeds fell into the set plate by the effect of outside vortex. The optimal parameter combination of simulation were 12 m·s-1 of the feeding speed, -1 800 Pa of the outlet pressure, 350 mm of the cylinder height, and 65° of the lower vertebral angle resulting in cleanliness and loss rate of 92.18% and 1.99%, respectively, and the errors were 2.947% and 7.428%, respectively compared with the field observation. Therefore, the results can provide a theoretical basis for optimizing design of small combine harvester. |