Results 1 to 10 of about 342 (150)

Utilization of Geogrid and Water Cushion to Reduce the Impact of Nappe Flow and Scouring on the Downstream Side of a Levee

Fluids, 2022
Water overflowing from a levee generates scour holes on the toe, which progresses towards the backward crest of the levee and results in nappe flow generation. The direct collision of nappe flow on the downstream area causes levee failure.
Fakhar Muhammad Abbas, Norio Tanaka
doaj   +4 more sources

Spatial distribution characteristics of splashing rainfall caused by nappe flow impingement on a plunge pool

Frontiers in Environmental Science, 2023
Splashing is the main atomization source for a jet impinging on a liquid layer. Increased understanding of splashing rainfall characteristics can help to reduce the hazard of flood discharge atomization in hydraulic engineering.
Qian Sun, Qian Sun, Hao Yuan, Hao Yuan, Wangru Wei, Liangliang Hu, Chunhang Xie, Chunhang Xie   +7 more
doaj   +4 more sources

Evaluating the Effectiveness of Seepage Countermeasures and Retrofitting Strategies for Mitigating Nappe Flow-Induced Reverse Flow and Erosion for Overtopping Flow from a Levee

Geosciences
Levee failure due to nappe flow and subsequent erosion presents a significant challenge to flood protection infrastructure. This study evaluates the effectiveness of horizontal drainage layers, a common seepage control method, in mitigating these risks ...
Liaqat Ali, Kento Sekine, Norio Tanaka
doaj   +4 more sources

Flow patterns in nappe flow regime down low gradient stepped chutes [PDF]

Journal of Hydraulic Research/De Recherches Hydrauliques, 2008
Although modern gravity dam spillways include often steep chutes operating in skimming flow regime, succession of free-falling nappes (i.e. nappe flow regime) are more common on low gradient chutes and cascades, and this flow situation received little attention to date.
Hubert Chanson
exaly   +5 more sources

Nappe Flow Surges down a Rough-Stepped Sloping Channel [PDF]

Journal of Hydrologic Engineering - ASCE, 2017
AbstractNappe flow applies to small discharges, and investigation of nappe flow surges helps to understand the mechanism of water flow in stepped open channels.
, Xie-Kang Wang, Chao Liu
exaly   +3 more sources

Prediction of the transition nappe/skimming flow on a stepped channel [PDF]

Journal of Hydraulic Research/De Recherches Hydrauliques, 1996
On a stepped channel, two distinct flow regimes may occur : nappe flow for low discharges and flat slopes, and skimming flow for larger flow rates. A simple analytical method to predict the onset of skimming flow is presented. The method is based upon the change of momentum direction at the impact of the jet on the downstream step.
Hubert Chanson
exaly   +5 more sources

Design of structural parameters and study on the energy dissipation characteristics of vertical jet-type energy dissipators [PDF]

Scientific Reports
In order to isolate energy dissipators from hydraulic engineering projects and address the issues of vibration damage caused by the discharge structures.
Haijun Ma, Xihuan Sun, Yongye Li
doaj   +2 more sources

Comparison of energy dissipation between nappe and skimming flow regimes on stepped chutes [PDF]

Journal of Hydraulic Research/De Recherches Hydrauliques, 1994
For the last decades, stepped spillways have become a popular method for handling flood releases. The flow regime over a stepped chute can be either a nappe flow or skimming flow regime. The energy dissipation of both flow regimes are analysed. The results are compared with experimental data.
Hubert Chanson
exaly   +5 more sources

Modelling of Bottom Shear Stresses in Scoured Hole Formed by Nappe Flow During Levee Overtopping

GeoHazards
Increases in flood magnitude due to climate change increase the necessity of resilient river levees to prevent the breaching that can contribute to reduced flood inundation volume even when overtopping from a levee occurs.
Yoshiya Igarashi, Norio Tanaka
doaj   +2 more sources

Nappe flows on a stepped chute with prototype-scale steps height: Observations of flow patterns, air-water flow properties, energy dissipation and dissolved oxygen

Journal of Hydro-Environment Research, 2019
Abstract Air-water flows occur commonly in stepped spillways including the nappe flow regime for low flow rates. The present laboratory experiments researched the nappe flow regime in a stepped chute with prototype-scale steps height providing unique insights into the evolution of nappe flows along a stepped chute.
Stefan Felder, M Geuzaine, Benjamin Dewals   +2 more
exaly   +3 more sources