Discussion of 'Turbulent Jet Energy Dissipation at Vertical Drops'

摘要

The authors are to be congratulated for developing a method for estimating the energy loss of a vertical drop with subcritical flow at the upstream channel. The experimental observations of Essery and Horner (1971) on a stepped spillway and Moore (1943) and Rand (1955) on a single step indicate that the energy loss in a jet flow regime is attributable to the impact of the jet, the breaking of the jet in air, mixing of the jet with recirculating backwater, and formation of a partial hydraulic jump on the deflected jet. Thus, this type of flow is complex in nature and difficult to analyze mathematically. The writers suggested Eq. (8) (based on a shear-layer model and applicable for d_c/h > 0.3) and Eq. (14) (based on a surface jet model and applicable for d_c/h < 0.3) for estimation of energy loss.