Publications related to Dynamic pressure

Toward Wearable Biosensing by Spectroscopy-free Raman Shift Detection and Soft Optofluidics

This thesis introduces spectroscopy-free Raman biosensing, which may find increasing use in the next generation of wearable devices for preventive healthcare. While wearables have made substantial advancements in detecting physical biomarkers, they have ye ...

EPFL2024

Highly Efficient Miniaturized Magnetorheological Valves Using Electropermanent Magnets

Yves Perriard, Christian Köchli, Sofia Lydia Ntella, Adrien Jean-Michel Thabuis, Kenny Jeanmonod, Bhawnath Tiwari

Fluidic systems enable actuation in various applications, such as automotive, medical, and industrial robotics. Miniaturized valves constitute a fundamental controlling element of modern fluidic systems, intriguing the interest of many researchers. This le ...

2023

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

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, 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

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

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

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

Pressure on obstacles induced by granular snow avalanches

Michael Lukas Kyburz

The increasing population and the consequential demand for dwelling and recreation areas lead to more frequent conflicts between humans and natural hazards. In mountainous regions snow avalanches are, therefore, still a major threat to humans and infrastru ...

EPFL2021

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

Electron flux and pressure dynamic in the LHC vacuum pilot sector as a function of beam parameters and beam pipe properties

Ambrogio Fasoli, Elena Buratin, Vincent Baglin

The Large Hadron Collider (LHC) is affected by the electron cloud (EC) phenomenon that can provoke beam instabilities, detrimental heat loads and pressure increases in the vacuum system. An innovative dedicated system called vacuum pilot sector (VPS) provi ...

2020

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

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

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

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

Evaluation of a Dynamic Transfer Matrix for a Hydraulic Turbine

François Avellan, Andres Müller, Keita Yamamoto

It is well known that hydraulic machines experience various types of flow instabilities causing a negative influence on the system under off-design operations. The transfer matrix method correlating the flow properties in upstream and downstream of hydraul ...

2020

Shape optimisation of technical devices via gradient descent using convolutional neural network proxies

Pascal Fua, François Fleuret, Pierre Bruno Baqué

The present invention generally relates to a method, a system and a computer program for shape optimisation of a technical device adapted to be exposed to a fluid flowing around a contour of said device with respect to its fluid dynamic parameters. In orde ...

2019

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

Folded-Tube Soft Pneumatic Actuators for Bending

Wyatt Marshall Felt

This article presents a model and experimental results for a new class of bending soft pneumatic actuators (SPAs) made from a single section of thin-walled flexible tubing. The actuator is formed by creasing the tubing into fin-like rectangular folds and i ...

MARY ANN LIEBERT, INC2019