Assessment of physical and aerodynamic properties of corn kernel (KSC 704)

Physical and aerodynamic properties of agricultural products have been used to precision design of the machinery and different postharvest operations. In this study, some physical and aerodynamic properties of corn kernels were investigated as a function of size at three levels of small, medium, and large (8.41 mm, 9.60 mm, and 11.62 mm, respectively) and moisture content in the range of 10 to 25% (wet basis). According to results, with increasing the moisture content from 10 to 25%, the length; width; thickness; geometric mean diameter; mass; and volume of the small, medium, and large kernels linearly increased by 2.22%, 2.40%, and 1.68%; 3.76%, 1.82%, and 1.55%; 3.98%, 2.49%, and 2.67%; 3.29%, 2.23%, and 1.93%; 8.44%, 7.38%, and 8.12%; and 11.32%, 10.71%, and 10.21%, respectively. In this regard, the projection area of the specimens increased nonlinearly by 6.06%, 4.26%, and 3.26%, respectively; whereas, true density decreased nonlinearly by 2.65%, 2.91%, and 1.90%, respectively. The maximum terminal velocity (12.41 m/s) and Reynolds number (6,037.44) were observed in large kernels and the moisture content of 25%; whereas, the minimum terminal velocity (8.32 m/s) and Reynolds number (3,016.55) were observed in small kernels and the moisture content of 10%. Maximum and minimum drag coefficients (1.014 vs. 0.302) were observed in small kernels at the moisture of 10% and large kernels at the moisture of 25%, respectively. The polynomial model was chosen as a suitable model in order to foretell the terminal velocity, Reynolds number, and drag coefficient of kernels as a function of moisture content and size. PRACTICAL APPLICATIONS: Mechanical damages to seeds at harvesting, transporting, and threshing are major concerns for farmers and farming experts. All the processes of wind transfer, flotation, and seed removal from seed mixture and the stalks and husks depend on the behavior of the seeds in the wind flow. Therefore, it is crucial to determine the physical and aerodynamic properties of various crops to analyzing their behavior during transport, processing, and precise design of farm equipment and machines to minimize wastes.