Application of the Generalized Flow Equation to All Flow Conditions at Spillways

Flow at a spillway can be classified into four conditions: submerged weir, free weir, submerged orifice and free orifice. There is also a transition between any two adjacent flow conditions. Since the early 1930s, extensive investigations on spillway flow computation have been conducted, resulting in a plethora of equations for each of the flow conditions. At the transition between two flow conditions, computed discharges for the two conditions are not consistent. Ansar and Chen (2009) proposed a new generalized flow equation, which is applicable to all flow conditions at a spillway, including transitional flows. This paper presents comparison results between computed discharges at spillways using the generalized flow equation and measured discharges in the field in south Florida and the Utah Water Resources Laboratory. The computed discharges agree well with flow measurements.