Velocity distribution over cylindrical weirs

Assuming that the flow field over the crest of a cylindrical weir is irrotational, a method was developed to predict the velocity distribution on the basis of the potential flow past a cylindrical weir obstacle. Predictions according to Dressler's theory over a curved bed are also presented for comparison. Physical models of cylindrical weirs with various radii and heights were considered. Velocity distributions were measured with a Prandtl tube. The proposed method agrees well with most of the experimental observations. The weir discharge coefficient was determined as a function of total head of approach flow and the crest radius.