Mohammad Reza Kamandar

This experiment was conducted to examine how factors, including orifice area, aspect ratio, grain moisture content, and grain variety, influence the flow rate. Flow rates were measured for samples passing through rectangular horizontal orifices. An adjustable rectangular orifice with a maximum width of 50 mm and a length of 76 mm was used, with the shorter side varied in increments of 10 mm, ranging from 10 mm upward. The flow rate of wheat was significantly influenced by the orifice area and the moisture content. The decrease in flow rate with an increasing moisture content can be well described by a second-degree polynomial equation. The coefficients for several derived equations, which predict wheat flow rate through orifices based on measured parameters and their combinations, were determined. A linear relationship is found between the flow rate (m³/h) and the product of the effective orifice area (Aₑ, cm²) and the square root of (g·Dₑ), i.e., 𝐴𝑒√𝑔𝐷𝑒 . The flow rate of wheat varieties for a given dimension of orifice decreased as the aspect ratio increased. Flow rate increased as the area of the orifice increased from 1.15 to 23.15 cm2; however, a higher flow rate was obtained at a lower aspect ratio. The variation in flow rates among wheat varieties was minimal across the different orifice sizes. This study establishes a universal correlation based on the Beverloo and ASABE models that accurately (𝑅2 > 0.99) predicts the flow of wheat through rectangular orifices in a hopper.