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

The influence of the gas on the dynamics of cavitation bubbles

Cavitation bubbles, extensively investigated in fluid mechanics, present enduring challenges in hydraulic machinery, while holding considerable potential for practical applications in biomedicine and sonochemistry. Despite more than a century of research, ...

EPFL2023

Advances in Spillway Hydraulics: From Theory to Practice

Anton Schleiss, José Pedro Gamito de Saldanha Calado Matos

Over the past decades, significant advances have been achieved in hydraulic structures for dams, namely in water release structures such as spillway weirs, chutes, and energy dissipators. This editorial presents a brief overview of the eleven papers in thi ...

2023

Plunging Circular Jets: Experimental Characterization of Dynamic Pressures Near the Stagnation Zone

Giovanni De Cesare, Pedro Filipe De Almeida Manso, Gregoire Aurelien Marie Jamet

Spillways are a requirement for dams’ safety, mainly preventing overtopping during floods. A common spillway solution involves plunging jets, which dissipate a considerable flow energy in the plunge pool. Energy dissipation has to occur in a controlled man ...

2022

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

Overflow pressure characterization in lined plunge pools for slab sizing

Giovanni De Cesare, Pedro Filipe De Almeida Manso, Francisca Marco Cutillas

This study presents an experimental work on dynamic pressures at the bottom of a lined plunge pool that receives overflow rectangular impinging jets and aims at improving the design criteria for pool slabs. The experiments were conducted in a fairly large ...

International Association for Hydro-Environment Engineering and Research (IAHR)2022

Improving the Accuracy of Fracture Toughness Measurement in Burst Experiments

Guanyi Lu, Yixuan Zhang

Experimental studies suggest that the fracture toughness of rocks increases with the confining pressure. Among many methods to quantify this dependency, a so-called burst experiment (Abou-Sayed, 1978) may be the most widely applied in practice. Its thick w ...

SPRINGER WIEN2022

Hydro-mechanical coupling in porous rocks: hidden dependences to the microstructure?

Lucas Xan Pimienta

While hydro-mechanical coupling in rocks is generally well understood, exotic rock poroelastic responses-such as unexpected dependence to fluid diffusion time and low skeleton moduli-have been reported. Hydro-mechanical coupling, or poroelasticity, explain ...

OXFORD UNIV PRESS2021

Design and fabrication of a vigorous "cavitation-on-a-chip" device with a multiple microchannel configuration

Luis Guillermo Villanueva Torrijo, Merve Zuvin, Morteza Ghorbani, Mohammad Jafarpour, Farzad Rokhsar Talabazar

Hydrodynamic cavitation is one of the major phase change phenomena and occurs with a sudden decrease in the local static pressure within a fluid. With the emergence of microelectromechanical systems (MEMS), high-speed microfluidic devices have attracted co ...

SPRINGERNATURE2021

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

Physical Mechanism and Flow Control of Tip Vortex Cavitation

Ali Amini

Occurrence of cavitation in hydraulic machines is a challenging issue because it is often accompanied with loss of efficiency, noise emissions, vibrations, and erosion damages. Tip vortices, in particular, are an ideal site for the development of cavitatio ...

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

Experimental studies of hydro-mechanical couplings in Enhanced Geothermal Reservoirs

Mateo Alejandro Acosta

Enhanced Geothermal Systems (EGS) allow for worldwide geothermal electricity production. They target deep (3-5 km), fractured rock reservoirs whose permeability is artificially increased through hydraulic stimulations (fluid injections). The injections mod ...

EPFL2020

Fault's hydraulic diffusivity enhancement during injection induced fault reactivation: application of pore pressure diffusion inversions to laboratory injection experiments

François Xavier Thibault Passelègue

In situ observations of fluid induced fault slip reactivation, as well as the analysis of induced seismicity have demonstrated the complexity of fluid-fault interactions under geological conditions. If fluid flow commonly reactivates faults in the form of ...

OXFORD UNIV PRESS2020

Fundamental Applications of Nanopores: Controlled DNA Translocations to Nanofluidics

Sebastian James Davis

Nanopores are nanometer sized openings that are the connection between two electrolyte filled reservoirs. The measurement of the ion transport flowing through such a pore allows to probe physically or biologically interesting phenomena. These range from th ...

EPFL2020

Mechanical and hydraulic transport properties of transverse-isotropic Gneiss deformed under deep reservoir stress and pressure conditions

Marie Estelle Solange Violay, Mateo Alejandro Acosta

In central Europe, many geo-energy reservoirs have revealed to be hosted in transverse isotropic crystalline rock, where the rock's mechanical and hydraulic transport properties are poorly constrained. Here, we performed triaxial experiments on Cresciano G ...

2020

Hydraulic Jump Downstream of a Stepped Chute: An Experimental Study

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

The number of stepped spillways significantly increased in the past decades. Among other reasons, this is due to their energy dissipation potential leading to a reduction of the residual energy at the toe of the spillway. To date, only fragmentary designed ...

2019

Two-phase flow phenomena in hydraulic turbines and pump-turbines operating in synchronous condenser mode

Elena Vagnoni

Hydraulic turbines and pump-turbines are often required to operate in particular conditions at which they consume active power. To keep the power consumption at a minimum, it is necessary to dewater the runner to reduce the mechanical torque. One of these ...

EPFL2018

A new bioinspired method for pressure and flow sensing based on the underwater air-retaining surface of the backswimmer Notonecta

Goran Lovric

In technical systems, static pressure and pressure changes are usually measured with piezoelectric materials or solid membranes. In this paper, we suggest a new biomimetic principle based on thin air layers that can be used to measure underwater pressure c ...

2018

Rotating air-water ring in the vaneless gap of a pump-turbine operating in condenser mode

François Avellan, Elena Vagnoni, Loïc Andolfatto, Pierre Leroy

The rotating air-water ring, featuring a bubbly flow, in the vaneless gap of a reduced scale physical model of a pump-turbine operating in dewatered condition is investigated. High speed visualizations are performed together with pressure fluctuation measu ...

2018

The turbulent pressure support in galaxy clusters revisited

Claudio Gheller

Due to their late formation in cosmic history, clusters of galaxies are not fully in hydrostatic equilibrium and the gravitational pull of their mass at a given radius is expected not to be entirely balanced by the thermal gas pressure. Turbulence may supp ...

2018