A CFD-based model for predicting the effect of fine material distribution on stored grain aeration efficiency

Understanding airflow distribution in stored grain is crucial for effective aeration system design. The presence of non-uniform fine materials creates a heterogeneous granular structure that significantly influences airflow patterns. Mathematical modeling provides an effective approach to predict how various parameters influence aeration efficiency. This study investigated airflow distribution under different conditions, including variations in initial content of broken corn and foreign material (BCFM), grain flow rates during silo loading, fill pipe diameters, and air velocities entering the stored bulk. A dimensionless BCFM prediction model was integrated with Haque’s fine distribution model to simulate the influence of fine material variation on pressure drop in stored grain. Model validation was performed by comparing CFD predictions with experimental data. Statistical analysis yielded R² = 0.90, RMSE = 0.0267 m.s⁻¹, and MRDM = 9.93%, indicating good agreement between predicted and observed values. Results showed that uniform airflow was achieved at lower grain depths, with higher initial BCFM levels. Aeration uniformity also improved with increased fill pipe diameters and material flow rates. In contrast, poorly aerated areas in the silo centre expanded at higher initial BCFM levels and lower grain flow rates. The findings confirm that Haque's model, combined with the standard k-ε turbulence model, can effectively replace Ergun's equation in aeration simulations. Overall, the CFD model demonstrated strong predictive capability, providing a valuable tool for optimizing stored grain aeration systems. • A new approach for the direct and realistic effect of fine martials in grain storage was introduced in aeration modeling • Haque’s model along with standard k − ∈ turbulent model could be a substitute for Ergun’s equation in simulation of aeration • Aeration becomes more uniform for larger fill pipe diameters and at higher material flow rates