Christophe Ancey

EPFL ENAC IIC LHE
GC A1 401 (Bâtiment GC)
Station 18
1015 Lausanne

Expertise

fluid dynamics rheology hydraulics physics of particle transport steep slope flows (avalanches, floods) Risk analysis

Mission

The LHE is a laboratory of environmental fluid mechanics whose research strives toward a better understanding of physical processes in the environment, with particular emphasis on the problems encountered in hydraulics and the study of geophysical flows. The field of research covered within Ancey's team includes the following topics: - Rheology & fluid dynamics of geophysical flow and the resulting hazards, with the objective of modeling natural hazards induced by water such as mudflows and avalanches. - Physics of bed load transport, aiming at better management of sediments in waterways Our major area of interest is the rheology of particle suspensions, mainly the natural suspensions involved in geophysical flows such as avalanches, mudflows, and stream transport of materials. Three major research orientations can be designated 1° Rheology of concentrated suspensions : we are particularly interested in the laws of very concentrated suspension behavior such as granular suspensions, investigating both the problem of determining adapted rheological laws and modeling free surface gravity flows. 2° The inverse problem :very often in rheology, stresses and strains cannot be measured directly; measures must first be taken on the macroscopic scale to then deduce the behavior on the microscopic level. This type of problem is most often within the domain of inverse problems. Our research aims most particularly to propose inverse determination methods either to adjust model coefficients or to deduce the mechanical behavior. 3° Particle entrainment in dilute turbulent suspensions: a major problem in geophysical flows is solid particle entrainment. We are mainly interested in understanding the erosion of a rough particle bed and modeling the phenomenon (Exner equation)
Christophe Ancey has both a PhD and an engineering degree granted by the Ecole Centrale de Paris and the Grenoble National Polytechnic Institute. Trained as a hydraulics engineer, he did his doctoral work under the supervision of Pierre Evesque from 1994 to 1997 on rheology of granular flows in simple shearing. He was recruited in 1998 as a researcher in rheology at the Cemagref as part of the Erosion Protection team directed by Jean-Pierre Feuvrier, which has since become the laboratoire "Storm Erosion, Snow and Avalanche Laboratory". Parallel to this research activity, with Claude Charlier He set up a consulting firm for engineering contracting called Toraval (www.toraval.fr), which has become the major player in the avalanche field in France. Since 2004, He is a fluid-mechanics professor at EPFL and he is the director of the Environmental Hydraulics Laboratory. He is associate editor of Water Resources Research, one of the leading journal in the field.

Awards

Harold Jan Schoemaker Award

International Association for Hydro-Environment Engineering and Research (IAHR)

2021

Selected publications

Monte Carlo calibration of avalanches described as Coulomb fluid flows

Ancey, C.
Published in Philosophical Transactions of the Royal Society of London series A, 2005, in press in

Solving the Couette inverse problem by using a wavelet-vaguelette decomposition

Ancey, C.
Published in Journal of Rheology, 49, 441-460, 2005. in

Towards a conceptual approach to predetermining high-return-period avalanche run-out distances

Meunier, M., and C. Ancey
Published in Journal of Glaciology, 50, 268-278, 2004. in

Estimating bulk rheological properties of flowing snow avalanches from field data

Ancey, C., and M. Meunier
Published in Journal of Geophysical Research, 109, F01004, 2004. in

Powder-snow avalanches: approximation as non-Boussinesq clouds with a Richardson-number-dependent entrainment function

Ancey, C.
Published in Journal of Geophysical Research, 109, F01005, 2004. in

Fluctuations of the solid discharge of gravity-driven particle flows in a turbulent stream,

Boehm, T., C. Ancey, P. Frey, J.-L. Reboud, and C. Duccotet
Published in Physical Review E, 69, 061307, 2004. in

Computing extreme avalanches

Ancey, C., C. Gervasoni, and M. Meunier,
Published in Cold Regions Science and Technology, 39, 161-180, 2004 in

2016 - Publications

No notices loaded.

-

Asymmetric breaking size-segregation waves in dense granular free-surface flows

P. GajjarK. Van Der VaartA. R. ThorntonC. G. JohnsonC. Ancey  et al.

Journal Of Fluid Mechanics. 2016. DOI : 10.1017/jfm.2016.170.

2016 - Workshops, conferences

The nature and role of advection in advection-diffusion equations used for modelling bed load transport

C. AnceyP. BohorquezJ. Heyman

EGU General Assembly 2016, Vienna, Austria, April 17-22, 2016.

2015 - Publications

An Underlying Asymmetry within Particle-size Segregation

K. van der VaartP. GajjarG. Epely-chauvinN. AndreiniJ. Gray  et al.

Physical Review Letters. 2015. DOI : 10.1103/PhysRevLett.114.238001.

-

Stochastic-deterministic modeling of bed load transport in shallow water flow over erodible slope: linear stability analysis and numerical simulation

P. J. U. Bohórquez Rodriguez de MedinaC. Ancey

Advances in Water Resources. 2015. DOI : 10.1016/j.advwatres.2015.05.016.

-

Stochastic interpretation of the advection diffusion equation and its relevance to bed load transport

C. AnceyP. Bohorquez Rodriguez de MedinaJ. Heyman

Journal of Geophysical Research - Earth Surface. 2015. DOI : 10.1002/2014JF003421.

-

No notices loaded.

-

Sediment diffusion in deterministic non-equilibrium bed load transport simulations

P. Bohórquez Rodriguez de MedinaC. Ancey

Applied Mathematical Modelling. 2015.

2015 - Workshops, conferences

Refractive index matched suspensions as a tool for investigating entrainment by avalanches and debris flows

B. M. Bates

European Geosciences Union General Assembly 2015, Vienna, Austria, April 12-17, 2015.

-

Fluid dynamics of basal entrainment by geophysical gravity-driven flows

B. M. Bates / C. Ancey (Dir.)

Lausanne, EPFL, 2015. DOI : 10.5075/epfl-thesis-6765.

A viscoplastic lubrication model for entrainment by avalanches and debris flows, and comparison with experiments

B. M. Bates

European Geosciences Union General Assembly 2015, Vienna, Austria, April 12-17, 2015.

-

Morphodynamic instability in a novel Saint-Venant-Exner model for bedload transport

P. Bohórquez Rodriguez de MedinaC. Ancey

Advances in Numerical Modelling of Hydrodynamics workshop, Sheffield, UK, March 24-25.

-

Asymmetric Particle Behavior during Size Segregation

K. van der VaartP. GajjarN. GrayC. Ancey

Particles 2015, Barcelona, ES, September 28-30, 2015.

2014 - Publications

A microstructural approach to bed load transport: mean behaviour and fluctuations of particle transport rates

C. AnceyJ. Heyman

Journal Of Fluid Mechanics. 2014. DOI : 10.1017/jfm.2014.74.

-

Bed load transport over a broad range of timescales: Determination of three regimes of fluctuations

H. MaJ. HeymanX. FuF. MettraC. Ancey  et al.

Journal Of Geophysical Research-Earth Surface. 2014. DOI : 10.1002/2014Jf003308.

-

Spatial correlations in bed load transport: Evidence, importance, and modeling

J. HeymanH. B. MaF. MettraC. Ancey

Journal Of Geophysical Research-Earth Surface. 2014. DOI : 10.1002/2013Jf003003.

-

Visualization of the internal flow properties and the material exchange interface in an entraining viscous Newtonian gravity current

B. M. BatesC. AnceyJ. Busson

Environmental Fluid Mechanics. 2014. DOI : 10.1007/s10652-013-9297-0.

-

Sediment transport in mountain rivers

C. AnceyP. BohorquezE. Bardou

Ercoftac Bulletin. 2014.

-

Un port et des cabanes, à la découverte du lac Baïkal (Sibérie)

C. CapréA. Gonin

2017

Spatial correlations in bed load transport: Evidence, importance, and modeling

J. HeymanH. B. MaF. MettraC. Ancey

Journal Of Geophysical Research-Earth Surface. 2014. DOI : 10.1002/2013Jf003003.

Reply to Comment on "Effect of Dissolved Organic Matter on the Transformation of Contaminants Induced by Excited Triplet States and the Hydroxyl Radical"

S. CanonicaU. von GuntenJ. Wenk

Environmental Science & Technology. 2011. DOI : 10.1021/es202439z.

Insertion du littoral dans la maille urbaine (Porto).

P. OdermattN. Stuber

2001

-

How to verify the precision of density-functional-theory implementations via reproducible and universal workflows

E. BosoniL. BealM. BercxP. BlahaS. Bluegel  et al.

Nature Reviews Physics. 2023-11-14. DOI : 10.1038/s42254-023-00655-3.

Automated mixing of maximally localized Wannier functions into target manifolds

J. QiaoG. PizziN. Marzari

Npj Computational Materials. 2023-10-31. DOI : 10.1038/s41524-023-01147-9.

Les défis de l'expertise moderne

C. Ancey

TDC, Canaopé Editions, France. 2014.

-

Pourquoi des modèles de calcul d’avalanche plus complexes n’amènent pas à de meilleurs résultats ?

C. Ancey

Neige et Avalanches (Anena). 2014.

2014 - Workshops, conferences

Tracking bed load particles in a steep flume: Methods and results.

J. HeymanC. Ancey

2014. River Flow 2014, Lausanne, CH, September 3-5. p. 138.

-

Avalanche of fluid in the laboratory: the dam-break problem revisited.

C. Ancey

Simulation of avalanches : modelling and numerics, Sevilla, Spain, March 11-14.

-

Asymmetry in Size-Segregation Rates.

K. van der VaartP. GajjarG. Epely chauvinN. GrayC. Ancey

Gordon Research Conference: Granular & Granular-Fluid Flow, Easton, USA, July 20-25.

-

Entraining avalanches on slopes: results from experiments using PIV on viscoplastic gravity currents.

B. M. BatesC. Ancey

EGU General Assembly 2014, Vienna, AU, April 27 - May 2.

-

A model for entrainment in avalanches and debris flows based on PIV measurements of viscous gravity currents.

B. M. BatesC. Ancey

EGU General Assembly 2014, Vienna, AU, April 27 - May 2.

-

Fluctuations of particle transport rates in graved-bed rivers or the quest for equilibrium?

C. AnceyJ. HeymanP. Bohorquez

3rd IAHR Europe Congress, Porto, PT, April, 14-16.

-

Analysis of sediment transport from recorded signals of sediments in a gravel-bed river: role of sediment availability

E. TravagliniE. BardouC. AnceyP. Bohorquez

2014. IAEG XII Congress, Torino, Italy, September 15-19. p. 477-482. DOI : 10.1007/978-3-319-09054-2_98.

-

Breaking Size-Segregation Waves in Granular Avalanches

K. van der VaartC. G. JohnsonP. GajjarN. GrayC. Ancey

Annual European Rheology Conference 2014, Karsruhe, D, April 8 - 11.

2013 - Publications

The dam-break problem for concentrated suspensions of neutrally buoyant particles

C. AnceyN. AndreiniG. Epely Chauvin

Journal of Fluid Mechanics. 2013. DOI : 10.1017/jfm.2013.154.

-

Granular suspension avalanches. I. Macro-viscous behavior

C. AnceyN. AndreiniG. Epely Chauvin

Physics of Fluids. 2013. DOI : 10.1063/1.4793719.

-

Granular suspension avalanches. II. Plastic regime

N. AndreiniC. AnceyG. Epely Chauvin

Physics of Fluids. 2013. DOI : 10.1063/1.4793720.

-

Statistics of bedload transport over steep slopes: Separation of time scales and collective motion

J. HeymanF. MettraH. MaC. Ancey

Geophysical Research Letters. 2013. DOI : 10.1029/2012GL054280.

2013 - Workshops, conferences

Bedload transport powered by daily floods: unsteadiness and stochasticity.

J. HeymanE. BardouxC. Ancey

European Geosciences Union General Assembly EGU, Vienna, Austria, April 7-12.

-

Effect of available entrainable material on a viscous gravity current including run-out characteristics and internal flow properties.

B. M. BatesC. Ancey

European Geosciences Union General Assembly EGU, Vienna, Austria, April 7-12.

-

Segregation in a quasi-stationary avalanche on an inclined conveyor-belt.

K. van der VaartJ. M. N. T. GrayC. Ancey

European Geosciences Union General Assembly EGU, Vienna, Austria, April 7-12.

-

Why don't avalanche-dynamics models of higher complexity necessarily lead to better predictions?

C. Ancey

International Snow Science Workshop ISSW 2013, Grenoble, France, October 7-11.

-

Rhéologie des suspensions turbulentes (diluées et concentrées).

C. Ancey

GdR Transport Solide Naturel, Mini école d'été, Rennes, France, September 9-11.

-

Bedform migration in steep channels: from local avalanches to large scale changes.

F. MettraJ. HeymanC. Ancey

AGU Fall Meeting, San Francisco, USA, December 9-13.

-

Approximate solution of the probability density function of bedload transport rate over multiple time scales.

X. FuT. UnivH. MaJ. HeymanF. Mettra  et al.

AGU Fall Meeting, San Francisco, USA, December 9-13.

-

RAS and LES Simulation of the supercritical flow over the waving bed.

X. FuT. UnivH. MaT. UnivJ. Heyman  et al.

AGU Fall Meeting, San Francisco, USA, December 9-13.

-

Channel meta-stability: effects on bedload transport.

F. MettraJ. HeymanC. Ancey

The 8th Symposium on River, coastal and Estuarine Morphodynamics RCEM, Santander, Spain, June 9-13.

-

From standing to breaking antidunes, a Hopf bifurcation.

J. HeymanF. MettraC. Ancey

Symposium on River, coastal and Estuarine Morphodynamics RCEM, Santander, Spain, June 9-13.

-

Segregation in a quasi ‐ stationary avalanche on an inclined conveyor ‐ belt.

K. van der VaartJ. M. N. T. GrayM. UnivC. Ancey

2nd IMA conference on dense granular flows, Cambridge, UK, July 1-4.

-

From bedform evolution to channel slope fluctuations in steep-slope streams.

F. MettraJ. HeymanH. MaT. UnivC. Ancey

8th IAG International Conference on Geomorphology, Paris, France, August 27-31, 2013.

2012 - Publications

Are there "dragon-kings" events (i.e. genuine outliers) among extreme avalanches?

C. Ancey

European Physical Journal-Special Topics. 2012. DOI : 10.1140/epjst/e2012-01565-7.

-

Internal dynamics of Newtonian and viscoplastic fluid avalanches down a sloping bed

N. AndreiniG. Epely-ChauvinC. Ancey

Physics Of Fluids. 2012. DOI : 10.1063/1.4718018.

-

Viscoplastic dambreak waves: review of simple computational approaches and comparison with experiments

C. AnceyN. AndreiniG. Epely Chauvin

Advances in Water Resources. 2012. DOI : 10.1016/j.advwatres.2012.03.015.

-

Gravity flow on steep slope

C. Ancey

Buoyancy-Driven Flows; New York: Cambridge University Press, 2012. p. 372-432.

-

Exact solutions of ideal dam break flood for arbitrary cross-section.

H. MaJ. HeymanC. AnceyX. D. Fu

European Geosciences Union General Assembly 2012, Vienna, Austria, 22 – 27 April 2012.

2012 - Workshops, conferences

Characterization of bedload transport in steep-slope streams.

F. MettraJ. HeymanC. Ancey

European Geosciences Union General Assembly 2012, Vienna, Austria, 22 – 27 April 2012.

-

Laboratory-scale dam-break study of gravity currents with basal entrainment: PIV measurements of a viscous newtonian fluid over a horizontal bed of the same fluid.

B. M. BatesC. AnceyJ. Busson

Fall Meeting, AGU, San Francisco, 3-7, December.

-

Multi-scale fluctuations of bed load transport rate over steep slope.

H. MaJ. HeymanC. AnceyX. Fu

Fall Meeting, AGU, San Francisco, December 3-7, 2012.

-

Time scale analysis of bedload discharge: from intermittency to white noise.

J. HeymanC. Ancey

8th IAG International Conference on Geomorphology, Paris, France, August 27-31.

-

From local slope fluctuations to channel evolution in steep-slope streams.

F. MettraJ. HeymanC. Ancey

8th IAG International Conference on Geomorphology, Paris, France, August 27-31.

-

Bedload transport over steep slopes: time scales and collective motion.

J. HeymanC. Ancey

Saladyn 2012, Paris, France, November 5-7.

2011

Multi-component particle size segregation in shallow granular avalanches

J. M. N. T. GrayC. Ancey

Journal of Fluid Mechanics. 2011. DOI : 10.1017/jfm.2011.138.

-

Refractive-index and density matching in concentrated particle suspensions: a review

S. WiederseinerN. AndreiniG. Epely ChauvinC. Ancey

Experiments in Fluids. 2011. DOI : 10.1007/s00348-010-0996-8.

-

Experimental investigation into segregating granular flows down chutes

S. WiederseinerN. AndreiniG. Épely-ChauvinG. MoserM. Monnereau  et al.

Physics of Fluids. 2011. DOI : 10.1063/1.3536658.

2010

Stochastic modeling in sediment dynamics: Exner equation for planar bed incipient bed load transport conditions

C. Ancey

Journal of Geophysical Research -All Series-. 2010. DOI : 10.1029/2009JF001260.

-

Image processing for the study of bedload transport of two-size spherical particles in a supercritical flow

V. HergaultP. FreyF. MétivierC. BaratC. Ducottet  et al.

Experiments in Fluids. 2010. DOI : 10.1007/s00348-010-0856-6.

2009

The dam-break problem for viscous fluids in the high-capillary-number limit

C. AnceyS. CochardN. Andreini

Journal of Fluid Mechanics. 2009. DOI : 10.1017/S0022112008005041.

-

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

J. M. N. T. GrayC. Ancey

Journal of Fluid Mechanics. 2009. DOI : 10.1017/S0022112009006466.

-

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

C. AnceyS. Cochard

Journal of Non-Newtonian Fluid Mechanics. 2009. DOI : 10.1016/j.jnnfm.2008.08.008.

-

Experimental investigation of the spreading of viscoplastic fluids on inclined planes

S. CochardC. Ancey

Journal of Non-Newtonian Fluid Mechanics. 2009. DOI : 10.1016/j.jnnfm.2008.08.007.

-

Improved SPH methods for simulating free surface flows of viscous fluids

J. FangA. ParriauxM. RentschlerC. Ancey

Applied Numerical Mathematics. 2009. DOI : 10.1016/j.apnum.2008.02.003.

2008

Tracking the free surface of time-dependent flows: Image processing for the dam-break problem

S. CochardC. Ancey

Experiments in Fluids. 2008. DOI : 10.1007/s00348-007-0374-3.

-

Entrainment and motion of coarse particles in a shallow water stream down a steep slope

C. AnceyA. C. DavisonT. B. BöhmM. JodeauP. FREY

Journal of Fluid Mechanics. 2008. DOI : 10.1017/S0022112007008774.

-

An exact solution for ideal dam-break floods on steep slopes

C. AnceyR. M. IversonM. RentschlerR. P. Denlinger

Water Resources Research. 2008. DOI : 10.1029/2007WR006353.

2007

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

C. AnceyS. CochardM. RentschlerS. Wiederseiner

Physica D: Nonlinear Phenomena. 2007. DOI : 10.1016/j.physd.2006.11.002.

-

The Kulikovskiy-Sveshnikova-Beghin Model of Powder Snow Avalanches: Development and Application

B. TurnbullJ. N. McElwaineC. Ancey

Journal of Geophysical Research. 2007. DOI : 10.1029/2006JF000489.

-

Plasticity and geophysical flows: A review

C. Ancey

Journal of Non-Newtonian Fluid Mechanics. 2007. DOI : 10.1016/j.jnnfm.2006.05.005.

Teaching & PhD

PhD Students

Sofi Farazande, Yanan Chen, Michael Josef Kohler, Axel Loïc Giboulot

Past EPFL PhD Students

Steve Cochard, Sébastien Wiederseiner, Martin Rentschler, Nicolas Andreini, François Mettra, Joris Heyman, Belinda Margaret Bates, Kasper van der Vaart, Blaise Etienne Marceau Dhont, Gauthier Rousseau, Daniel Vito Papa, Zhenzhu Meng, Tomás Alfredo Trewhela Palacios, Michael Lukas Kyburz, Tomy Doda, Ivan Pascal, Romain Maxime Dubuis, Christian Mörtl, Mehrdad Kiani Oshtorjani, Clemente Gotelli

Past EPFL PhD Students as codirector

Richard Vonlanthen

Courses

Flood and dam break waves

CIVIL-515

The course provides computational methods for unsteady flow problems such as floods, waves, and dam failures. The emphasis is on the physical understanding of the phenomena, the governing equations (Saint-Venant equations) and aspects related to engineering practice.

Fluids mechanics (For GC)

CIVIL-210

This course is an introduction to fluid mechanics. Physical properties of fluids and the conservation principles (mass and momentum) are presented. The second part of the course is devoted to applications to open-channel hydraulics and pipeline flows.

Hydrological risks and structures

ENV-524

The course is an introduction to statistical hydrology with a focus on the hydrology of small mountain watersheds. The course includes a general introduction to risk management. It then introduces the student to extreme value theory and hydrological models.

Similarity and Transport Phenomena in Fluid

ME-716

The course is an introduction to symmetry analysis in fluid mechanics. The student will learn how to find similarity and travelling-wave solutions to partial differential equations used in fluid and continuum mechanics. The course covers mathematical and physical aspects