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Christophe Ancey

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Related publications (96)

Page 3 of 5

Experimental investigation into segregating granular flows down chutes

Christophe Ancey, Nicolas Andreini, Sébastien Wiederseiner, Gaudenz Moser, Gaël Epely Chauvin

We experimentally investigated how a binary granular mixture made up of spherical glass beads size ratio of 2 behaved when flowing down a chute. Initially, the mixture was normally graded, with all the small particles on top of the coarse grains. Segregati ...

2011

Segregation of large particles in dense granular flows suggests a granular Saffman effect

Christophe Ancey, Kasper van der Vaart

We report on the scaling between the lift force and the velocity lag experienced by a single particle of different size in a monodisperse dense granular chute flow. The similarity of this scaling to the Saffman lift force in (micro-) fluids, suggests an in ...

2018

Dynamics of glide avalanches and snow gliding

Christophe Ancey

In recent years, due to warmer snow cover, there has been a significant increase in the number of cases of damage caused by gliding snowpacks and glide avalanches. On most occasions, these have been full-depth, wet-snow avalanches, and this led some people ...

Amer Geophysical Union2015

Stokes' third problem for Herschel-Bulkley fluids

Christophe Ancey, Belinda Margaret Bates

Herschel-Bulkley materials can be set in motion when a sufficiently high shear stress or body force is applied to them. We investigate the behaviour of a layer of Herschel-Bulkley fluid when it is suddenly tilted and subject to gravitational forces. The ma ...

Elsevier2017

Using a Data Driven Approach to Predict Waves Generated by Gravity Driven Mass Flows

Christophe Ancey, Zhenzhu Meng

When colossal gravity-driven mass flows enter a body of water, they may generate waves which can have destructive consequences on coastal areas. A number of empirical equations in the form of power functions of several dimensionless groups have been develo ...

2020

Entrainment,motion, and deposition of coarse particles transported by water over a sloping mobile bed

Christophe Ancey, Joris Heyman

In gravel bed rivers, bed load transport exhibits considerable variability in time and space. Recently, stochastic bed load transport theories have been developed to address the mechanisms and effects of bed load transport fluctuations. Stochastic models i ...

Wiley-Blackwell2016

Modeling turbulent stream flows over rough permeable beds

Christophe Ancey, Ivan Pascal, Gauthier Paul Daniel Marie Rousseau

In steep streams, turbulent flows run over coarse sediments that are similar in size to flow depth. Under these conditions, a significant part of the flow may seep through the permeable bed. Based on experimental data, this paper presents a model able to r ...

CRC Press2020

Solving the Couette inverse problem using a wavelet-vaguelette decomposition

Christophe Ancey

This paper develops a new approach to computing the shear rate from the torque and rotationalvelocity measurements in a Couette rheometer. It is based on wavelet-vaguelette decomposition (WVD) proposed by Donoho (Donoho, D., Appl. Comput. Harmon. Anal. 2, ...

2005

Large particle segregation in two-dimensional sheared granular flows

Christophe Ancey, Tomás Alfredo Trewhela Palacios

We studied the segregation of single large intruder particles in monodisperse granular materials. Experiments were carried out in a two-dimensional shear cell using different intruder and media diameters, whose quotient defined a size ratio R that ranged f ...

2021

Continuous monitoring of bedload transport in a laboratory flume using an impact sensor

Christophe Ancey, Blaise Etienne Marceau Dhont, Gauthier Paul Daniel Marie Rousseau

Bedload transport rate in gravel-bed rivers shows large non-Gaussian fluctuations, even under steady flow conditions. The development of high-resolution measurement techniques during the last two decades creates research opportunities to study the intermit ...

American Society of Civil Engineers2016

Segregation, recirculation and deposition of coarse particles near two-dimensional avalanche fronts

Christophe Ancey

Stratification patterns are formed when a bidisperse mixture of large rough grains and smaller more mobile particles is poured between parallel plates to form a heap. At low flow rates discrete avalanches flow down the free surface and are brought to rest ...

Cambridge University Press2009

Existence and features of similarity solutions for non-Boussinesq gravity currents

Christophe Ancey, Steve Cochard, Martin Rentschler, Sébastien Wiederseiner

In this paper, the flow dynamics of gravity currents on a horizontal plane is investigated from a theoretical point of view by seeking similarity solutions. The current is generated by unleashing a varying volume of heavy fluid within an ambient fluid of m ...

2007

Refractive Index Matched (RIM) PIV in Free Surface Flows of Particle-Laden Yield Stress Fluids

Christophe Ancey, Yanan Chen

Flow of lava, avalanches, mudslides, and many geophysical and planetary flow systems are examples of free-surface flows of Yield Stress Fluids (YSFs). This category of fluids is known for its dual behavior below- and above a yielding threshold for the appl ...

2024

Impulse waves generated by snow avalanches: Momentum and energy transfer to a water body

Christophe Ancey

When a snow avalanche enters a body of water, it creates an impulse wave whose effects may be catastrophic. Assessing the risk posed by such events requires estimates of the wave’s features. Empirical equations have been developed for this purpose in the c ...

Wiley-Blackwell2016

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

The dam-break problem for Herschel-Bulkley viscoplastic fluids down steep flumes

Christophe Ancey, Steve Cochard

In this paper we investigate the dam-break problem for viscoplastic (Herschel- Bulkley) fluids down a sloping flume: a fixed volume of fluid initially contained in a reservoir is released onto a slope and flows driven by gravitational forces until these fo ...

2009

Rheophysics of highly concentrated coarse-particle suspensions in a wide-gap Couette rheometer

Christophe Ancey, Sébastien Wiederseiner

An optical visualization apparatus has been designed to measure the particle-velocity and solid-concentration profiles of highly concentrated coarse-particle suspensions in a wide-gap Couette rheometer. The main objective is to investigate the frictional-v ...

Amer Inst Physics, 2 Huntington Quadrangle, Ste 1No1 D, Melville, Ny 11747-4501 Usa2009

Breaking size-segregation waves and mobility feedback in dense granular avalanches

Christophe Ancey, Kasper van der Vaart

Through experiments and discrete particle method (DPM) simulations we present evidence for the existence of a recirculating structure, that exists near the front of dense granular avalanches, and is known as a breaking size-segregation (BSS) wave. This is ...

2018

Bed Topography Inference from Velocity Field Using Deep Learning

Christophe Ancey, Mehrdad Kiani Oshtorjani

Measuring bathymetry has always been a major scientific and technological challenge. In this work, we used a deep learning technique for inferring bathymetry from the depth-averaged velocity field. The training of the neural network is based on 5742 labora ...

2023

Segregation of sediments in meandering river channels

Christophe Ancey, Yanan Chen

Particle segregation is widespread in river channels and significantly influences bed grain size distribution. To date, most studies have investigated particle size segregation in straight river channels. Less studied is the case where particles segregate ...

2024