Modeling Airflow Path through Grain Bulks Using the Discrete Element Method

Knowledge of airflow through agricultural bulk solids, such as bulk grain, is important for designing storage and processing equipment. The complex and variable connectivity of pore structures of agricultural bulk solids makes airflow difficult to predict. This study aims to simulate the pore-structure of a grain bed and calculate the airflow paths at a microscopic scale. A discrete element model developed in PFC 3D (Particle Flow Code in 3 Dimensions) was used to simulate the pore-structure of the grain bed. Then a mathematical algorithm was developed to calculate the tortuosity of the widest airflow path through the pore structure of the grain bed. The calculated tortuosity was in good agreement with the range of the tortuosity values reported in the literature for porous beds consisting of spherical particles.