Velocity and Pressure Measurements on a Broad-crested Weir: Physical Measurements

Basic experiments were conducted on a large-size broad-crested weir with an upstream rounded corner. Detailed velocity and pressure measurements were performed for a range of flow conditions. The results showed the rapid flow re-distribution at the upstream end of the weir, as well as next to the weir brink at large flow rates. Assuming non-uniform velocity and nonhydrostatic pressure distributions, it is shown that critical flow conditions were achieved above the whole crest length. The velocity measurements highlighted a developing boundary layer. The data differed from the smooth turbulent boundary layer theory, although the present results were consistent with earlier studies.