Publications associées à Pesanteur

Stability of a liquid layer draining around a horizontal cylinder: Interplay of capillary and gravity forces

François Gallaire, Shahab Eghbali, Simeon Vladimirov Djambov

We study the drainage of a viscous liquid film coating the outside of a solid horizontal cylinder, where gravity acts vertically. We focus on the limit of large Ohnesorge numbers Oh, where inertia is negligible compared to viscous effects. We first study t ...

Amer Physical Soc2024

Propagation of planar three-dimensional buoyant hydraulic fractures

Andreas Möri

Hydraulic fractures are driven by an internal fluid pressure exceeding the minimum compressive stress, propagating in a direction perpendicular to the latter. This class of tensile fractures has gained interest over the last fifty years due to the developm ...

EPFL2023

Columnlike free-interface flows: symmetry breaking and linear instability

Shahab Eghbali

This thesis is dedicated to the analysis of a subclass of interfacial flows, columnlike free-interface flows, from two view angles: (i) the symmetry breaking under geometry-induced or external forces, (ii) their stability against infinitesimal disturbances ...

EPFL2023

Analytical Studies in Support of an Improved Approach to the Design of Acceleration-Sensitive Nonstructural Elements

Dimitrios Lignos, Ahmed Mohamed Ahmed Elkady

This paper summarizes a series of analytical studies that were conducted in connection with an improved approach for the design of acceleration-sensitive nonstructural elements. In the new approach, bracing to secure nonstructural elements to the structure ...

Applied Technology Council, Sponse2022

Experimental and numerical investigation of the unbalance behavior of rigid rotors supported by spiral-grooved gas journal bearings

Jürg Alexander Schiffmann, Elia Iseli

The forced response of rigid rotors, supported by herringbone-grooved gas journal bearings are investigated numerically and experimentally. The rotor configurations are varied by using end cylinders, attached at both sides of the shaft. Three rotors with d ...

ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD2022

Estimating the non-dimensional energy of vortex rings by modelling their roll-up

Karen Ann J Mulleners, Guillaume de Guyon-Crozier

The non-dimensional energy of starting vortex rings typically converges to values around 0.33 when they are created by a piston-cylinder or a bluff body translating at a constant speed. To explore the limits of the universality of this value and to analyse ...

Cambridge University Press2022

Human Head Yaw Estimation based on Two 3-axis Accelerometers

Hervé Lissek, Gilles André Courtois, Vincent Pierre Olivier Grimaldi

The estimation of the orientation of an object, and a human head in particular, can be defined by the Euler angles: the yaw, pitch and roll. The robust and drift-free estimation of those angles is usually achieved with the data from several sensors such as ...

2022

Experimental Study to Validate an Improved Approach to Design Acceleration-Sensitive Nonstructural Components

Dimitrios Lignos, Ahmed Mohamed Ahmed Elkady

Nonstructural components in buildings can be subjected to very large acceleration and deformation demands during earthquakes. This is particularly true for flexible components that are tuned or nearly tuned to one of the modal frequencies of the supporting ...

Applied Technology Council, Sponse2022

Paradoxical simulation results of chaos-like chattering in the bouncing ball system

Kilian Schindler

This paper reports and investigates paradoxical simulation results of the bouncing ball system. Chaos-like motion of the bouncing ball system with intermittent chattering (Zeno behavior) is observed in simulations if the relative acceleration of the table ...

ELSEVIER2021

Proof Of Concept Of A Graphene-Based Resonant Accelerometer

Luis Guillermo Villanueva Torrijo, Daniel Moreno Garcia

Acceleration measurements are fundamental in applications such as consumer electronics, navigation, automotive safety and Internet of things (IoT). In comparison with capacitive or piezoresistive MEMS accelerometers, resonant graphene accelerometers have t ...

IEEE2021

Force Scaling Comparison of Transport Phenomena in Proton Exchange Membrane Fuel Cell Flow Channels

Mahbod Heidari

Liquid-gas two-phase flow in flow channels of proton exchange membrane (PEM) fuel cells has been investigated extensively in the literature; however, a comparison between the order of the magnitude of the forces occurring within the flow channels has not b ...

ASME2021

Einstein-Cartan Portal to Dark Matter

Mikhail Chapochnikov, Andrey Shkerin, Inar Timiryasov, Sebastian Zell

It is well known since the works of Utiyama and Kibble that the gravitational force can be obtained by gauging the Poincare group, which puts gravity on the same footing as the standard model fields. The resulting theory-Einstein-Cartan gravity-inevitably ...

AMER PHYSICAL SOC2021

Quasi-stationary flow structure in turbidity currents

Giovanni De Cesare, Shun Nomura

A turbidity current is a particle-laden current driven by density differences due to suspended sediment particles. Turbidity currents can transport large amounts of sediment down slopes over great distances, and play a significant role in fluvial, lake and ...

IRTCES2020

Advances in understanding cement hydration mechanisms

Karen Scrivener, Patrick Juilland, Aslam Kunhi Mohamed, Alexandre Reda Constantin William Caleb Ouzia

Progress in understanding hydration mechanisms of alite and Portland cement is reviewed. Up to the end of the induction period, dissolution rates determined by the undersaturation of the solution dominate the reaction, but, better understanding is needed a ...

Pergamon-Elsevier Science Ltd2019

Micropipette calibration by differential pressure measurements

Philippe Renaud, David Vincent Bonzon

The pipetting of small volumes, typically ranging between a few and one thousand microliters (mu l), is widely used in many laboratories and essentially relies on air displacement to aspirate and dispense the liquid contained in a small plastic tip. ...

IOP PUBLISHING LTD2019

Paradoxical Chaos-Like Chattering In The Bouncing Ball System

Kilian Schindler

This paper reports and investigates paradoxical simulation results of the bouncing ball system. Chaos-like motion of the bouncing ball system with intermittent chattering (Zeno behaviour) is observed in simulations if the relative acceleration of the table ...

AMER SOC MECHANICAL ENGINEERS2018

Optimizing the acceleration and resolution of three-dimensional fat image navigators for high-resolution motion correction at 7T

José Pedro Rebelo Ferreira Marques, Daniel Gallichan

PURPOSE: To investigate the effect of spatial resolution and parallel imaging acceleration factor on the quality of the motion estimates derived from image navigators with a three-dimensional (3D) gradient-recalled echo (GRE) acquisition with fat excitatio ...

Wiley-Blackwell2017

A wrist sensor and algorithm to determine instantaneous walking cadence and speed in daily life walking

Kamiar Aminian, Pierre-André Farine, Benedikt Fasel, Cyntia Duc, Flavien Bardyn, Farzin Dadashi, Martin Savary

In daily life, a person’s gait—an important marker for his/her health status—is usually assessed using inertial sensors fixed to lower limbs or trunk. Such sensor locations are not well suited for continuous and long duration measurements. A better locatio ...

Springer Heidelberg2017

Drift Reduction for Inertial Sensor Based Orientation and Position Estimation in the Presence of High Dynamic Variability During Competitive Skiing and Daily-Life Walking

Benedikt Fasel

Nowadays inertial sensors are extensively used for gait analysis. They can be used to perform temporal event detection (i.e. step detection) and to estimate the orientation of the feet and other body segments to determine walking speed and distance. Usuall ...

EPFL2017

Centrifuge modeling of mitigation-soil-foundation-structure interaction on liquefiable ground

Significant progress has been made in recent years toward a better understanding of the liquefaction phenomena. Yet, the combined effects of excess pore pressure generation, permanent soil deformation, and ground shaking, with and without mitigation, on th ...

Elsevier Sci Ltd2017