Publications associées à Hydraulic Jump Downstream of a Stepped Chute: An Experimental Study

Bottom-Pressure Development Due to an Abrupt Slope Reduction at Stepped Spillways

Anton Schleiss, José Pedro Gamito de Saldanha Calado Matos, Michael Pfister, Mohammad Javad Ostad Mirza

Fluctuating bottom-pressures on stepped chutes are relevant for the spillway design. An abrupt slope reduction causes a local alteration of the bottom-pressure development. Little information is available regarding the air–water flow properties near an abr ...

2022

From coating flow patterns to porous body wake dynamics via multiscale models

Pier Giuseppe Ledda

Multiscale phenomena are involved in countless problems in fluid mechanics. Coating flows are known to exhibit a broad variety of patterns, such as wine tears in a glass and dripping of fresh paint applied on a wall. Coating flows are typically modeled und ...

EPFL2022

Stilling Basin Performance Downstream of Stepped Spillways

Ivan Stojnic

Advances in dam construction techniques have significantly increased the number of implemented stepped spillways worldwide. A key hydraulic feature of a stepped chute, compared to a smooth chute, is the enhanced energy dissipation resulting in a reduced re ...

EPFL2020

Bottom pressure characteristics in a stilling basin downstream of a stepped spillway for two different chute slopes

Anton Schleiss, José Pedro Gamito de Saldanha Calado Matos, Michael Pfister, Ivan Stojnic

In the last decades numerous stepped spillways were built, mostly on the downstream face of roller compacted concrete (RCC) dams. Stilling basins are often used as an energy dissipater. Although the hydraulics of stepped chutes was extensively investigated ...

The University of Queensland2020

Effect of 30-Degree Sloping Smooth and Stepped Chute Approach Flow on the Performance of a Classical Stilling Basin

Anton Schleiss, José Pedro Gamito de Saldanha Calado Matos, Michael Pfister, Ivan Stojnic

Advances in dam construction techniques have significantly increased the number of stepped spillways implemented worldwide. Although stepped chutes provide enhanced energy dissipation along the chute, as compared to smooth chutes, an adequate energy dissip ...

2020

Experimental study on the influence of abrupt slope changes on flow characteristics over stepped spillways

Mohammad Javad Ostad Mirza

Application of stepped spillways increases the energy dissipation rate along the spillway and may reduce the dimensions of the terminal energy dissipation structure. This pronounced energy dissipation makes stepped chutes attractive under various condition ...

EPFL2016

Air entrainment and pressure development in skimming flow on an abrupt slope change on stepped spillways

Anton Schleiss, José Pedro Gamito de Saldanha Calado Matos, Michael Pfister, Mohammad Javad Ostad Mirza

Numerous stepped spillways were built to date, namely on RCC gravity dams or on valley flanks besides embankment or rockfill dams, while some others are currently under design or construction. In some cases, slope changes may be required on stepped chutes, ...

2015

Influence of jet aeration on pressures around a block embedded in a plunge pool bottom

Anton Schleiss, Rafael Xavier Meriade Duarte

The influence of the air entrained by water jets on the dynamic pressures applied on the bottom of a plunge pool and inside underlying fissures was analyzed with systematic experiments. The large experimental facility reproduced aerated high-velocity jets ...

Springer Verlag2015

The effect of pressure gradient on the collapse of cavitation bubbles in normal and reduced gravity

Marc Tinguely

When water flows through hydraulic turbomachines, the local pressure can become low enough to vaporize the water and create vapor cavities. This phenomenon is called cavitation. When the cavities collapse, shock waves and liquid jets traveling through the ...

EPFL2013

Aerated flows on stepped chutes with macro-roughness elements, Part II : Energy dissipation

Anton Schleiss, Stéphanie Joëlle André

An experimental research of flow on different systems of stepped overlays for 18.6 degrees and 30 degrees slopes was conducted. In addition to define flow characteristics (Part I), the study highlighted the existence of an homogeneous aerated flow in which ...

2008

Analytical approximations for flow in compressible, saturated, one-dimensional porous media

David Andrew Barry

A nonlinear model for single-phase fluid flow in slightly compressible porous media is presented and solved approximately. The model assumes state equations for density, porosity, viscosity and permeability that are exponential functions of the fluid (eith ...

2007

Rehabilitation of St-Marc dam: Model studies for the spillways

Marcelo Leite Ribeiro, Sameh Ahmad Kantoush

The Saint-Marc dam, owned by EDF-France is a concrete gravity dam built between 1926 and 1930. It is located near Limoges (France) on the Taurion River and has currently two gated spillways, one 7.50 m wide on the right bank and the other with two passes o ...

2007

Sintering of NaCl powder: Mechanisms and first stage kinetics

Jean-François Despois, Andreas Mortensen

Isothermal NaCl sintering experiments are conducted between 500 and 790 degrees C on powders 75, 100, 150 and 400 mu m in average diameter. Along with literature data, the results are compared with theoretical predictions for the initial stage of sintering ...

2006

Numerical simulation of free surface incompressible liquid flows surrounded by compressible gas

Alexandre Caboussat, Marco Picasso, Jacques Rappaz

A numerical model for the three-dimensional simulation of liquid-gas flows with free surfaces is presented. The incompressible Navier-Stokes equations are assumed to hold in the liquid domain. In the gas domain, the velocity is disregarded, the pressure is ...

2005

High velocity aerated flow on stepped chutes with macro-roughness elements

Stéphanie Joëlle André

Uncontrolled overtopping during flood events can endanger embankment dams. Erosion of the downstream slope and scouring of its base caused by the high velocity and energy of the overflow can indeed lead to breach formation until complete failure. In this c ...

EPFL2004