Study of Flow Over Weirs such as Pulteney Weir

The present research paper looks into the expression of a head-discharge relationship for
Pulteney Weir, constructed in Bath in 1975 as a part of a flood protection scheme to reduce the city’s risk of flooding, and initiates research for the computation of its flow. To achieve this, the study looks at the flow of three known shapes of weirs – a sharp-crested rectangular, a sharp-crested 45° oblique weir and a sharp-crested 60° oblique weir - and compares experimental and analytical expressions, to eventually test “Half” Pulteney and Pulteney Weir models. The series of tests were conducted in the University of Bath’s Hydraulic Laboratory. For each experiment, upstream and downstream water levels were measured for different flow rates and boundary conditions. Head – discharge relationships were established for all weirs tested. The results showed that for the sharp-crested 45° and 60° oblique weirs, the discharge coefficient is simply a function of H/P. The derived equation for Pulteney Weir indicated that the impact of a serious flood situation in Bath could be predicted. Although the “Half” Pulteney experiments presented that the turbulent flow was not as symmetrical as it was expected to be. All equations found, proved a very a good agreement with the experimental data.