Evaluating Airflow Uniformity in Covered Outdoor Piles through Computational Fluid Dynamics Simulations

Highlights Airflow uniformity was determined using CFD simulations and uniformity index. The uniformity of airflow for the different duct and fan designs in the covered outdoor pile was determined. Regions with poor airflow were identified for each duct and fan design. Grain pile design that gave the highest uniformity index and the least region of poor airflow was identified. ABSTRACT. Adequate and uniform airflow within covered outdoor piles is critical for preserving grain quality during storage. Poor airflow uniformity can lead to uneven moisture distribution, temperature gradients, and localized hotspots within the grain mass, creating an environment conducive to the growth of molds, fungi, and insect infestations. Consequently, such compromised storage conditions can lead to significant economic losses for grain elevators and impact the availability and affordability of grain-based products in the market. However, despite considerable literature addressing airflow uniformity in permanent storage structures, aeration system designs for covered outdoor piles have not generally included in-depth analyses affecting airflow distribution. This study aimed to investigate the airflow uniformity in covered outdoor piles using computational fluid dynamics (CFD) simulations. A rectangular grain pile, commonly used in Kansas, was modeled using ANSYS Fluent. Various configurations of covered outdoor piles were evaluated regarding airflow velocity and uniformity. The velocity magnitude, vector plots, and contour plots of velocity were used to visualize the air velocity in the different regions of the grain pile. The uniformity index was used to determine the degree of uniformity. Results showed which configuration has better uniformity and less incidence of poor air velocities in the grain mass. By determining the airflow distribution within the grain mass, we can identify potential areas for improvement in the design of covered outdoor piles. Keywords: Airflow, CFD, Grain pile, Storage, Uniformity.