Publications by Fadi Hachem | EPFL Graph Search

Signal analysis of an actively generated cavitation bubble in pressurized pipes for detection of wall stiffness drops

Giovanni De Cesare, Anton Schleiss, 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 ...

Elsevier2016

Hydraulic design of the diaphragm’s orifice at the entrance of the surge shaft of FMHL pumped-storage power plant

Giovanni De Cesare, Christophe Nicolet, Rafael Xavier Meriade Duarte, Fadi Hachem

The surge tank located at the upstream head of penstocks and shafts of hydropower plants is an effective measure to protect the headrace tunnels against high pressure fluctuations. It reflects the transient pressure waves that are generated by the variatio ...

TPU2013

Etude sur modèle physique du nouvel évacuateur de crue du barrage de Gage II

Fadi Hachem, Violaine Dugué, Michael Pfister

Suite à des études hydrologies récentes, le barrage de Gage II en France révèle un déficit de capacité d'évacuation des crues. Il a donc été décidé de construire un évacuateur de creue complémentaire en rive droit du barrage. Cet ouvrage est composé d'un P ...

Soc Hydrotechnique France2013

Detection of Local Wall Stiffness Drop in Steel-Lined Pressure Tunnels and Shafts of Hydroelectric Power Plants Using Steep Pressure Wave Excitation and Wavelet Decomposition

Anton Schleiss, Fadi Hachem

A new monitoring approach for detecting, locating, and quantifying structurally weak reaches of steel-lined pressure tunnels and shafts is presented. These reaches arise from local deterioration of the backfill concrete and the rock mass surrounding the li ...

2012

Monitoring of Steel Lined Pressure Shafts Considering Water-Hammer Wave Signals and Fluid-Structure Interaction

Fadi Hachem

In the past, the safety margin for dynamic water pressure loads in steel-lined pressure tunnels and shafts was considered as acceptable by using conventional design safety factors. Due to high peak energy demands, existing plants are operating nowadays und ...

EPFL2011

A review of wave celerity in frictionless and axisymmetrical steel-lined pressure tunnels

Anton Schleiss, Fadi Hachem

Generally applicable approaches for estimating the‘‘quasi-static’’, which means without fluid–structure interaction and frequency-dependent water-hammer wave speed in steel-lined pressure tunnels are analyzed. The external constraints and assumptions of th ...

Elsevier2011