Publications associées à Experimental assessment of an active (acoustic) liner prototype in an acoustic flow duct facility

In flow acoustic characterisation of a 2D active liner with local and non local strategies

Hervé Lissek, Maxime Volery, Gaël Matten

The design and the grazing flow aeroacoustical characterization of a 2D active liner based on an array of electroacoustic absorbers are presented in this paper. The strategy stands on a pressure-based, current-driven digital architecture for impedance cont ...

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

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

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

Transport barrier in 5D gyrokinetic flux-driven simulations

Two ways for producing a transport barrier through strong shear of the E x B poloidal flow have been investigated using GYSELA gyrokinetic simulations in a flux-driven regime. The first one uses an external poloidal momentum (i.e. vorticity) source that lo ...

IOP Publishing Ltd2022

The concept of the mobilized domain: how it can explain and predict the forces exerted by a cohesive granular avalanche on an obstacle

Christophe Ancey, Johan Alexandre Philippe Gaume, Betty Sovilla, Michael Lukas Kyburz

The calculation of the impact pressure on obstacles in granular flows is a fundamental issue of practical relevance, e.g. for snow avalanches impacting obstacles. Previous research shows that the load on the obstacle builds up, due to the formation of forc ...

2022

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

An Instrumented High-Speed Rotor with Embedded Telemetry for The Continuous Spatial Pressure Profile Measurement in Gas Lubricated Bearings: A Proof of Concept

Jürg Alexander Schiffmann, Karim Magdi Zakaria Abdelrahman Shalash

Pressure is one of the constitutional quantities governing the flow field in gas lubricated bearings. Knowledge of the pressure is of principal importance in the fundamental understanding of such bearings and for the calibration of reduced order models. Th ...

2020

In situ control of the helical and skyrmion phases in Cu2OSeO3 using high-pressure helium gas up to 5 kbar

Henrik Moodysson Rønnow, Arnaud Magrez, Ivica Zivkovic, Jonathan White

We report a small-angle neutron scattering study of the helical and skyrmion lattice order in single-crystal Cu2OSeO3 under quasihydrostatic helium gas pressures up to 5 kbar. By using helium gas as the pressure-transmitting medium (PTM) we ensure pressure ...

AMER PHYSICAL SOC2020

Swirl number based transposition of flow-induced mechanical stresses from reduced scale to full-size Francis turbine runners

François Avellan, Christian Landry, Arthur Tristan Favrel, Keita Yamamoto, Joao Gomes Pereira Junior

At part load conditions, Francis turbines are subject to the emergence of a hydrodynamic instability in their draft tube, referred to as precessing vortex rope. It induces pressure pulsations in the water passages at the precession frequency of the vortex, ...

2020