Experiment and Numerical Simulation Study on Hydraulic Characteristics of the Spillway Jet Nappe

Physical model test and numerical simulation are used to study the hydraulic characteristics of the jet nappe of a spillway. The jet nappe from continuous flip bucket adopted in the original design which produced serious scouring to downstream bed and left bank slope, is modified into a beveled bucket with sidewall diffused to relieve the scouring problem. RNG k-epsilon turbulent model and VOF method were applied to simulate the water-air two-phase jet nappe from the beveled flip bucket to a plunge pool. The calculated shape of water tongue, horizontal length, incidence velocity of the jet nappe, and the velocity distribution of downstream are in good agreement with the data obtained in experiment results. It concludes that the jet nappe from beveled bucket with sidewall diffused can be fully spread on cross direction and fallen into the middle of the river so as to reduce the scouring to downstream bed and bank slope. Furthermore, numerical simulation can replace model experiment effectively to some extent, it also can provide some data for engineering optimal design.