Experimental Study On The Characteristic Of The Shock Wave And Water Wing In Slit Type Energy Dissipator

The theory and technique of slit type energy dissipater are widely used for the energy dissipation in hydropower stations, especially in those with high water head, narrow valley and large unit-width discharge. People have done much work on the energy dissipation mechanism and body design of this energy dissipater. Recently, it is found that the secondary water-wing produced in some spillway with slit-type dissipater may diffuse laterally and strike the bank slope, which will endanger the stability of the slope as well as the safety of the surrounding structures. Some preliminary study shows that the movement of the water-wing is obviously related to the upstream shock wave. Due to the no attention to the harmfulness of the water-wing, few achievements are obtained in earlier literature.This project will focus on the shock wave and the water-wing in slit-type dissipater, and study the effect of the body parameters and inflow characteristic on the shock wave and the water-wing experimentally and numerically. Then the formation mechanism and motion law of water-wing will be revealed, and the relationship between the shock wave and the water-wing will be established associating with the inflow and body parameters. Finally, the project will propose some principle and methods to effectively control the water-wing diffusion.The results of this project will demonstrate the internal relationship between the jet shock wave and the water-wing motion in slit-type dissipater theoretically. It will also provide theoretical basis and technical support for the disaster prevention and risk avoiding of discharging constructions with slit-type energy dissipater.Research shows that:(1) By comparing the different working conditions tests has further enriched the narrow outcome study on energy dissipation and hydraulics characteristics of obtained hydraulics(flow Froude number Fr), shape parameters(narrow contraction ratio ? and slit-bucket angle ?) and contraction of the water lines, wall and floor water pressure, picked from the tongue of the relevant laws.(2) By analysing practical data has given the narrow parameters of energy dissipation and intersection of torrent shock wave from the narrow entrance of distance and depth of relationships,and optimize torrent shock wave angle formula reduces the absolute value of error of calculated and observed values to 5%.(3) It's the first time in this experiment under different conditions that measured rainfall distribution on the side of the narrow water wings and drawing rainfall contour map and three-dimensional maps, rapid flow shock wave and rainfall distribution relationship is established, which is given a narrow intersection of torrent shock wave position for a contracted period and degree of turbulence effects on rainfall distribution.