Discharge Coefficient of a Trapezoidal Broad-Crested Side Weir for Low Approach Froude Numbers

Even though broad-crested side weirs have been subjected to numerous studies, guidance for discharge coefficient determination for broad-crested side weirs still has not been clearly given. Experimental research was carried out to describe the flow conditions in front of a trapezoidal broad-crested side weir at low Froude numbers in the approach channel for various combinations of inflow and overflow discharges. Three side weir variants with different oblique angles were studied. Flow characteristics at the side weir were analyzed and assessed based on the results obtained from extensive measurements performed on a hydraulic model. The empirical relation between the coefficient of obliqueness, the angle of side weir obliqueness, and Froude numbers upstream and downstream of the weir was derived.