Shock waves and water wing in slit-type energy dissipaters

Experimental investigation of the abnormal rise of water-wings downstream of a step-type aerator

“…In terms of flood discharge and energy dissipation, the majority of these large hydropower projects are characterised with high water head, large flow rate, high discharge power, and complex geological conditions. Generally, the maximum velocity of flood discharge flow can reach up to 50 m/s, and this leads to a few destructive issues, for example cavitation erosion on the chute surface , difficulties in energy dissipation and scour prevention (Zhang & Niu 2014), eruption and rise of a water-wing (Han et al 2006), atomisation of flood discharge (Huang et al 2017a(Huang et al , 2017b, and vibration of hydraulic structures (Ma et al 2020). These issues have become significant to the design and operation safety of hydropower projects.…”

“…These issues have become significant to the design and operation safety of hydropower projects. Turbulent motions of high-speed flood discharge flow are usually manifested as cavitation, aeration, water-wing eruption, and strong pressure fluctuations (Huang et al 2017a(Huang et al , 2017b. In particular, eruption and rise of a water-wing, caused by step-type aerators under high water head conditions, could potentially lead to safety issues of certain structures (Toyoshima et al 2003;Hunt & Kadavy 2015).…”

“…In the prototype observation of a huge water conservancy project (Huang et al 2017a(Huang et al , 2017b, it was observed that, during the flood discharge under high water head conditions, flow in the open-channel section of the deep outlets showed abnormally strong fluctuations after passing through the step-type aerator. The surface of the flow went up and down intermittently, with the water-wing impacting on the cover plate of the chute.…”

Substantiation of counter­vortex spillway structures of hydrotechnical facilities

“…issues of reliability and cost-effectiveness of spillway structures, their throughput, the force effect of the water flow on the structures and elements of the tailrace system, and the choice of the method for damping kinetic energy. In most cases, the energy of the flow dissipates outside the flow channel of the spillway (in the downstream) [1]. There are examples where damping occurs within the flow path through the spillway system [2].…”

Effects of Bucket Type and Angle on Downstream Nappe Wind Caused by a Turbulent Jet

“…The constant width bucket has a simple structure and cavitation erosion resistance [15], but its scour is relatively serious for the downstream riverbed. The contracted slit bucket deforms the approach flow by a transverse contraction and longitudinal extension at the lip of the flip bucket, increasing the longitudinal diffusion of the trajectory nappe [21,22]. The expansion flip bucket is proposed and its possessive energy of the unit width discharge is reduced by expanding the cross-section of the trajectory nappe.…”