Publications associées à Centre de poussée

Determination of Parameters Characteristic of Dynamic Weakening Mechanisms During Seismic Faulting in Cohesive Rocks

Marie Estelle Solange Violay, François Xavier Thibault Passelègue, Chiara Cornelio

While sliding at seismic slip-rates of ∼1 m/s, natural faults undergo an abrupt decrease of shear stress called dynamic weakening. Asperity-scale processes related to flash heating and weakening and, meso-scale (mm-cm) processes involving shear across the ...

AGU2022

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

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

Three-dimensional fluid-driven stable frictional ruptures

Brice Tanguy Alphonse Lecampion, Alexis Alejandro Sáez Uribe

We investigate the quasi-static growth of a fluid-driven frictional shear crack that propagates in mixed mode (II+III) on a planar fault interface that separates two identical half-spaces of a three-dimensional solid. The fault interface is characterized b ...

2022

Benchmark study of undrained triaxial testing of Opalinus Clay shale: Results and implications for robust testing

Lyesse Laloui, Alessio Ferrari, Alberto Minardi

Triaxial testing of argillaceous rocks and shales is significantly more challenging than conventional rock mechanical testing. The challenges are mainly related to the very low permeability of these geomaterials, and their sensitivity to exposure of atmosp ...

ELSEVIER2021

Hydraulic fracture growth in quasi-brittle materials

Dong Liu

Hydraulic fracturing is a technique often used in the oil and gas industry to enhance the production of wells in low-permeability reservoirs. It consists of fluid injection at a sufficiently large injection rate to create and propagate tensile fractures in ...

EPFL2021

Single-phase SPH modelling of plunge pool dynamic pressures at a near-prototype scale

Pedro Filipe De Almeida Manso

The turbulent plunging jet of a nearly incompressible fluid into a stagnant fluid is of great importance in many practical applications, especially for the engineering of hydropower. As an example, the dynamic load exerted by the impact of turbulent high-v ...

Taylor & Francis Ltd2021

The dynamics and timescales of static stall

Karen Ann J Mulleners, Sébastien Le Fouest, Julien Dominique Claude Deparday

Airfoil stall plays a central role in the design of safe and efficient lifting surfaces. We typically distinguish between static and dynamic stall based on the unsteady rate of change of an airfoil’s angle of attack. Despite the somewhat misleading denotat ...

2021

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

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

Mechanical behaviour of fluid lubricated faults during earthquake nucleation and propagation

Chiara Cornelio

The need for new forms of energy, and in particular the need for renewable and clean ones, led to develompment of Enanched Geothermal Systems, where the well designed stimulation of a geothermal reservoir is the key parameter for the safe development of th ...

EPFL2020

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

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

Fault reactivation during fluid pressure oscillations: transition from stable to unstable slip

Marie Estelle Solange Violay, François Xavier Thibault Passelègue, Carolina Giorgetti, Corentin Jean-Marie Rémi Noël

High‐pressure fluid injection in deep geo‐reservoirs can induce earthquakes. Recent observations suggest that cyclic injections might trigger less seismicity than monotonic injections. Here, we report triaxial laboratory experiments conducted on faulted qu ...

2019

Mitigating tip vortex cavitation by a flexible trailing thread

Mohamed Farhat, Ali Amini

Tip Vortex Cavitation (TVC) is a major issue in design and operation of axial hydraulic machines. We investigate the capacity of a flexible trailing thread in alleviating TVC by analyzing the flow-induced motion. For this purpose, a nylon thread with three ...

AMER INST PHYSICS2019

Fiber bundle model under fluid pressure

Internal fluid pressure often plays an important role in the rupture of brittle materials. This is a major concern for many engineering applications and for natural hazards. More specifically, the mechanisms through which fluid pressure, applied at a micro ...

Amer Physical Soc2016

Avalanches in dry and saturated disordered media at fracture

Jean-François Molinari, Enrico Milanese, Okan Yilmaz

This paper analyzes fracturing in inhomogeneous media under dry and fully saturated conditions. We adopt a central force model with continuous damage to study avalanche behavior in a two-dimensional truss lattice undergoing dilation. Multiple fractures can ...

Amer Physical Soc2016

ALE/finite element modeling of an unconfined bubble plume in periodic domain: bubble shape and oscillation analysis

John Richard Thome, Gustavo Rabello Dos Anjos, Gustavo Charles Peixoto de Oliveira

This paper introduces a numerical model developed based upon the arbitrary Lagrangian-Eulerian/finite element scheme to analyze bubble plumes in a periodic domain. A spherical air bubble is immersed into a large pool of quiescent water to act as an unconfi ...

Springer Heidelberg2015

Hemodynamic transition driven by stent porosity in sidewall aneurysms

Mohamed Farhat, Pierre Bouillot

The healing process of intracranial aneurysms (IAs) treated with flow diverter stents (FDSs) depends on the IA flow modifications and on the epithelization process over the neck. In sidewall IA models with straight parent artery, two main hemodynamic regim ...

Elsevier2015

Measurement of the dynamics in ski jumping using a wearable inertial sensor-based system

Kamiar Aminian, Julien Favre, Julien Chardonnens

Dynamics is a central aspect of ski jumping, particularly during take-off and stable flight. Currently, measurement systems able to measure ski jumping dynamics (e.g., 3D cameras, force plates) are complex and only available in few research centres worldwi ...

Taylor & Francis2014