new approach for estimating of energy dissipation over stepped spillways

hydraulics of stepped spillway is a very complicated phenomenon, as it consists of a two phase flow passing through a set of designed steps. the steps increase the rate of energy dissipation taking place on the spillway face. turbulence, flow aeration and energy dissipation are the main tasks in the design of such structures. this study consists of the experimental investigation to determine the energy dissipation over stepped spillways. experiments conducted at water research institute on two physical models of the siyah bisheh stepped spillways in iran. to develop a more generalized expression, the results of previous investigations were also considered in our study. therefore, a wide range of variables were taken into account to estimate the energy dissipation along the non-uniform flow regime. assuming the energy dissipation along the uniform flow regime to be equal to the vertical displacement of the jet, the total energy lost was calculated. a comparison of the results with those of measurements showed a regression of 0.92 for the total energy dissipation, which is one of the features of the present method for estimating of the energy dissipation, compared with the previous investigation.