Publications associées à The influence of added mass on rock block uplift in plunge pools

Laterally unconfined neutral or negative buoyancy inflow into a quiescent ambient over sloping bottom

This work studies the nearshore hydrodynamics of a shallow turbulent flow entering a laterally unconfined quiescent ambient with a sloping bottom boundary. Examples of such flow are neutrally buoyant ebb tidal jets and hyperpycnal river plumes entering ope ...

EPFL2023

A Fast Hybrid Pressure-Correction Algorithm for Simulating Incompressible Flows by Projection Methods

Jiannong Fang

To enforce the conservation of mass principle, a pressure Poisson equation arises in the numerical solution of incompressible fluid flow using the pressure-based segregated algorithms such as projection methods. For unsteady flows, the pressure Poisson equ ...

2023

The biofilm ecology of proglacial floodplain streams

Jade Brandani

Glacial forelands figure among the most dynamic landscapes on Earth, and their formation is currently accelerating given glacier shrinkage. Draining these forelands are streams hosting unique microbial communities, which have the capacity to impact both th ...

EPFL2023

Experimental Study on Bedload Transport and Bedforms: Behaviour and Interplay in Steep Turbulent Streams

Ivan Pascal

In mountain regions, steep streams play an important role in water and sediment connectivity. In these highly dynamic systems, water flow features, sediment fluxes and stream morphologies are tightly interlinked over a broad range of temporal and spatial s ...

EPFL2022

Morphology and morphodynamics of braided rivers: an experimental investigation

Daniel Vito Papa

Braided rivers form some of the most fascinating fluvial patterns found on Earth. They are identifiable by their unique morphology of complex networks of intertwined channels that spread across wide floodplains. Detailed knowledge of their dynamics is need ...

EPFL2020

Pioneer plant Phalaris arundinacea and earthworms promote initial soil structure formation despite strong alluvial dynamics in a semi-controlled field experiment

Claire Guenat, Pascal Turberg, Renée-Claire Le Bayon, Muhammad Riaz, Andreas Cedric Schomburg

Soil structure formation is among the most important processes in riverfloodplains which are strongly influ-enced by alluvial dynamics. In the context of river restoration projects, a better understanding of soil structureformation in habitats adjacent to ...

2019

Statistical and physical characterization of rainfall-driven overland flow morphologies

Mohsen Cheraghi

Environmental transport processes are highly coupled with the shape of landscapes. Modern catchment analysis with high-resolution data and huge computational powers demand more detailed within-cell metrics for surface evolution modeling. This dissertation ...

EPFL2019

Composition and superposition of alluvial deposits drive macro-biological soil engineering and organic matter dynamics in floodplains

Claire Guenat, Rodolphe Schlaepfer, Pascal Turberg, Renée-Claire Le Bayon, Andreas Cedric Schomburg

Soil structure formation in alluvial soils is a fundamental process in near-natural floodplains. A stable soil structure is essential for many ecosystem services and helps to prevent river bank erosion. Plants and earthworms are successful soil engineering ...

2019

Coherent Structure Interaction During Unsteady Separation

Karen Ann J Mulleners

Unsteady flow separation in rotationally augmented flow fields plays a significant role in the aerodynamic performance of industrial rotors, including wind turbines. Current computational models underestimate the aerodynamic loads due to the inaccurate pre ...

2019

Turbulent Flows over Rough Permeable Beds in Mountain Rivers: Experimental Insights and Modeling

Gauthier Paul Daniel Marie Rousseau

Steep mountain streams exhibit shallow waters with roughness elements such as stones and pebbles that are comparable in size to flow depth. Owing to the difficulty in measuring fluid velocities at the interface, i.e., from the rough permeable bed to the fr ...

EPFL2019

Catchment drainage network scaling laws found experimentally in overland flow morphologies

David Andrew Barry, Paolo Perona, Andrea Rinaldo, Mohsen Cheraghi

The scaling relation between the drainage area and stream length (Hack’s law), along with exceedance probabilities of drainage area, discharge and upstream flow network length are well known for channelized fluvial regions. We report here on a laboratory e ...

2018

Geomorphic work by gravity currents with varying initial conditions

Jessica Zordan

Gravity currents are density-driven flows that are able to transport high amounts of sediment and are responsible of great geomorphic changes. Moreover they can have severe repercussions on the environment since they are conveyors of substances, e.g. pollu ...

EPFL2018

Morphogenetic degeneracies in the actomyosin cortex

Sundar Ram Naganathan

One of the great challenges in biology is to understand the mechanisms by which morphogenetic processes arise from molecular activities. We investigated this problem in the context of actomyosin-based cortical flow in C. elegans zygotes, where large-scale ...

ELIFE SCIENCES PUBLICATIONS LTD2018

The origin of fine sediment determines the observations of suspended sediment fluxes under unsteady flow conditions

Mário Jorge Rodrigues Pereira Da Franca, Carmelo Juez Jiménez

Field observations in a wide range of environments have shown that sediment availability is a major control on the suspended sediment observations in streams. Here we examine, via laboratory experiments, how the amount of proximal in-channel fine sediment ...

American Geophysical Union2018

Entrainment, transport and deposition of sediment by saline gravity currents

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Jessica Zordan, Carmelo Juez Jiménez

Few studies have addressed simultaneously the feedback between the hydrodynamics of a gravity cur- rent and the geomorphological changes of a mobile bed. Hydrodynamic quantities such as turbulent and mean velocities, bed shear stress and turbulent stresses ...

2018

Hydromorphodynamic effects of the width ratio and local tributary widening on discordant confluences

António Heleno Cardoso, Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Sebastián Guillén Ludeña

River training works performed in the last couple of centuries constrained the natural dynamics of channel networks in locations that include the confluences between tributaries and main channels. As a result, the dynamics of these confluences are currentl ...

Gfg2017

Hydrodynamics of mountain-river confluences and its relationship to sediment transport

Mário Jorge Rodrigues Pereira Da Franca, Sebastián Guillén Ludeña

Mountain confluences are characterized by narrow and steep tributaries that provide important sediment load to the confluence, whereas themain channel supplies the dominant flow discharge. This results in a marked bed discordance between the tributary and ...

American Geophysical Union2017

INFLUENCE OF THE INITIAL VOLUME OF LOCK EXCHANGE GRAVITY CURRENTS ON THE SEDIMENT ENTRAINMENT CAPACITY

Jessica Zordan

In the lock-exchange technique used to produce gravity currents, two fluids of different densities are initially at rest in a tank and separated by a vertical barrier, the lock gate. When this gate is suddenly removed, the two fluids come into contact and, ...

2017

A multiscale model for sediment impact erosion simulation using the finite volume particle method

François Avellan, Ebrahim Jahanbakhsh, Sebastián Camilo Leguizamón Sarmiento, Siamak Alimirzazadeh, Audrey Paulette Solange Maertens

The erosion of a surface by a sediment-laden flow is an inherently multiscale phenomenon which includes physical interactions covering many orders of magnitude in both length and time scales. Conforming to the nature of the problem, we propose a novel mult ...

2017

EXPERIMENTAL RESULTS ON SEDIMENT ENTRAINMENT BY GRAVITY CURRENTS

Anton Schleiss, Mário Jorge Rodrigues Pereira Da Franca, Jessica Zordan, Carmelo Juez Jiménez

Gravity currents are geophysical flows responsible of the distal transport of high volumes of sediments. In particular, turbidity currents, a form of gravity currents where sediments in suspension confer the buoyancy that ignites the flow, are the main mec ...

2017