Publication
Effect of drop in pipe wall stiffness on water-hammer speed and attenuation
Publications associées (35)
Signal analysis of an actively generated cavitation bubble in pressurized pipes for detection of wall stiffness drops
Anton Schleiss, Giovanni De Cesare, Mohamed Farhat, Fadi Hachem, Alexandre Jean Pachoud
Due to the increasing production of volatile new renewable energies as solar and wind, storage hydropower plants have to operate under harsh operation conditions in order to stabilize the electricity grid. As a result, highly transient water pressures occu ...
Elsevier2016Wave propagation in the vicinities of rock fractures under obliquely incident wave
Lyesse Laloui, Jian Zhao, Yang Zou, Jing Li
Though obliquely incident plane wave across rock fractures has been extensively investigated by theoretical analysis, the quantitative identification of each wave emerged from fractures has not been achieved either in numerical simulation or laboratory exp ...
Springer Verlag2016Analytical analysis of slow and fast pressure waves in a two-dimensional cellular solid with fluid-filled cells
Vladimir Dorodnitsyn, Bart Van Damme
Wave propagation in cellular and porous media is widely studied due to its abundance in nature and industrial applications. Biot's theory for open-cell media predicts the existence of two simultaneous pressure waves, distinguished by its velocity. A fast w ...
Acoustical Soc Amer Amer Inst Physics2016Fluid-structure interaction during hydraulic transients in pressurized pipes: experimental and numerical analyses
Pressurized pipes may be endangered by failure due to excessive hydraulic transients, the so-called waterhammer. These pressure waves are strongly affected by fluid-structure interaction (FSI), unsteady skin friction, dry friction or pipe-wall viscoelastic ...
EPFL-LCH2016Experimental distinction of damping mechanisms during hydraulic transients in pipe flow
Anton Schleiss, Pedro Filipe De Almeida Manso, David Ferràs Segura
The aim of the present paper is to contribute to the identification of the principal mechanical- hydraulical relationships du ring hydraulic transients by means of the analysis of observed transient pressure and strain waves in different pipe rigs. Four di ...
Elsevier2016Hydroacoustic Modeling of a Cavitation Vortex Rope for a Francis Turbine
Hydraulic machines subject to off-design operation involve the presence of cavitating flow regimes in the draft tube. The cavitation vortex rope at part load conditions is described as an excitation source for the hydraulic system, and interactions between ...
EPFL2015Identification of the wave speed and the second viscosity in cavitating flow with 2D RANS computations - Part II
François Avellan, Sébastien Alligné
The 1D modelling of cavitation vortex rope dynamics in Francis turbine draft tube is decisive for prediction of pressure fluctuations in the system. However, models are defined with parameters which values must be quantified either experimentally or numeri ...
Iop Publishing Ltd2015Elastodynamics of a Two-Dimensional Square Lattice With Entrained Fluid-Part I: Comparison With Biot's Theory
Alessandro Spadoni, Vladimir Dorodnitsyn
In the present paper, the performance of Biot's theory is investigated for wave propagation in cellular and porous solids with entrained fluid for configurations with well-known drained (no fluid) mechanical properties. Cellular solids differ from porous s ...
Asme2014Elasto-Dynamic Behavior Of A 2D Square Lattice With Entrained Fluid
Numerical investigation of wave propagation in a cellular solid with closed cells configuration and entrained fluid showed an existence of two types of pressure waves, which have opposite polarization and have different phase and group velocities. This is ...
Int Center Numerical Methods Engineering2014Effects of coordination and pressure on sound attenuation, boson peak and elasticity in amorphous solids
Connectedness and applied stress strongly affect elasticity in solids. In various amorphous materials, mechanical stability can be lost either by reducing connectedness or by increasing pressure. We present an effective medium theory of elasticity that ext ...
Royal Society of Chemistry2014