Energy dissipation of skimming flows on stepped-channel chutes

The energy loss of skimming flows, in which the main flow skims on the stepped-channel chute, has been investigated by many researchers. But general agreement concerning experimental results has not been obtained. In this paper, the energy loss of skimming flows is investigated systematically under a wide range of discharges, channel slopes, step heights, and dam heights. The energy loss of skimming flows is clarified, and the change of the energy loss with dam height and step height is discussed. Also, the total energy loss of a skimming flow and jump if a hydraulic jump is formed immediately below the stepped channel end is shown. The results reveal that the utilization of a stepped channel is effective in dissipating the energy of a supercritical flow on spillways or channel chutes.