Three-dimensional airflow distribution in a maize silo with peaked, levelled and cored grain mass configurations

Non-uniform airflow models for peaked, levelled and cored grain mass configurations in a maize silo were developed using the finite volume method. Airflow resistance due to porous media of grain material was implemented using Ergun’s equation. The linear porosity variation was implemented with low porosity at the centre and maximum at the side. Non-uniform airflow distribution for natural air drying with an airflow rate of 1.1 m3 min−1 t−1 was validated with experimental data using maize in grain bins with storage capacities of 180.0–450.0 Mt. Air velocity was predicted with reasonable accuracy for cored, levelled and peaked grain mass configurations having porosities ranging from 0.34 in the core to 0.38 towards the silo wall. Incorporation of variable porosities into the model improved the air velocity prediction. For the cored grain mass and variable porosity (0.34–0.38), the error was 4.4% at the centre and 23.1% at the periphery.