Experiments for the Discharge Capacity of the Siphon Spillway Having the Creager - Ofitserov Profile

One type of spillways for dams in physical models is deliberately tested. It is a siphon spillway having the Creager - Ofitserov profile, studied in four alternative models with various configurations based on variation of the cross section. The study highlighted a clear distinction for not and almost complete prime areas for low head and complete prime areas for the remainder of the values of the head applied to the level upstream. It is to be announced that the coefficients of discharge of the siphons models increase very quickly while going from the first to the fourth model, for this purpose the optimal cross section corresponding to the maximum coefficient of discharge was fixed. The variation at the same time of the coefficient of discharge, the ratio of the head on vertical dimension at the crown of the siphon and the Froude number were formulated. At the particular case of priming, this formulation deduces a new relationship making possible to envisage the Froude number for a known coefficient of discharge.