The characters of energy dissipation under different flows on stepped spillways

The authors conducted a series of expriments on energy dissipation due to hydraulic jump.Comparison was made between energy dissipation ratios before and behind a hydraulic jump of critical jump created in downstream stilling basins under different flows of nappe flow,skimming flow and transition flow on a stepped spillway with an angle θ=19°.The discharge,step height and dam height were also changing.The experiment results proved that the differences between the energy dissipation ratios under the three flows were very small and the total energy dissipation ratio would amount to 95% at its maximum while the energy dissipation ratio before a jump shared over 85%.