Distribution and Movement Characteristics of Airflow and Mixture in Sugarcane Harvester Extractor Based on CFD-DEM

Mechanized harvesting of sugarcane is facing the challenge of high impurity content and cane loss. Therefore, based on computational fluid dynamics (CFD) and discrete element method (DEM), this study aims to explore the movement characteristics of airflow and mixture in the extractor to optimize its performance. The distribution and movement of airflow and mixture in extractor under different structures and operating parameters were simulated and analyzed by CFD-DEM. The simulation results showed that rotational speed affected airflow and material velocity, but did not affect airflow field distribution and material movement trajectory. The number of blades and impeller ratio affect the internal airflow field and material movement trajectory. The blade installation angle affects the vortex range and flow analysis phenomenon at the top of the extractor. Finally, the extractor was optimized by Box–Behnken design with the residence time of materials as the index. The test results showed that when the rotating speed was 1450 and 1650 r/min, the speed at the lower outlet of improved extractor increased by 30.1% and 28.5%. The performance of the improved extractor improved slightly at low feed rate and low rotation speed (1 kg/s,1250r/min). At the high feed rate (3 km/h), the impurity content at the corresponding three speeds decreased significantly by 7.0%, 19.6%, and 18.1%, respectively. The cane loss of the improved extractor was reduced by 11.22% under high speed and high feed rate (3 kg/s, 1650 r/min). These findings provide new insights and theoretical foundations for optimizing the sugarcane harvester extractor.