SIMULATION AND OPTIMIZATION OF A PNEUMATIC CONVEYING DEVICE FOR A PLOT WHEAT BREEDING HARVESTER BASED ON CFD–DEM

To address the problem of grain residue commonly occurring during the operation of plot wheat breeding harvesters, the CFD–DEM coupling method was employed to investigate the airflow distribution characteristics and material conveying behavior within a pneumatic conveying device. Fan rotational speed, feeding rate, and the curvature radius of the lower conveying pipe were selected as experimental factors for single-factor and response surface experiments. The results showed that all selected factors significantly affected the conveying performance and residue rate. Specifically, the residue rate decreased with increasing fan rotational speed, increased with increasing feeding rate, and decreased as the curvature radius of the lower pipe increased. The response surface analysis indicated that the optimal operating parameters were a fan rotational speed of 2400 r/min, a feeding rate of 0.4 kg/s, and a lower pipe curvature radius of 420 mm, under which the minimum residue rate of 0.021% was achieved.