Publications related to Boundary-layer approach to the linear karren instability

Periodic orbits exhibit oblique stripe patterns in plane Couette flow

Spatiotemporally chaotic dynamics of transitional plane Couette flow may give rise to regular turbulent-laminar stripe patterns with a large-scale pattern wavelength and an oblique orientation relative to the laminar flow direction. A recent dynamical syst ...

AMER PHYSICAL SOC2021

Continuously-fed density currents over impermeable and porous substrates

Sara Venuleo

Gravity currents are buoyancy-driven flows having a significant impact on the environment and human life. They can be observed in a vast range of natural and anthropogenic scenarios, such as seawater and freshwater, the atmosphere, or industrial processes. ...

EPFL2020

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

Exact invariant solution reveals the origin of self-organized oblique turbulent-laminar stripes

Tobias Schneider, Tobias Klaus Kreilos, Florian Reetz

Wall-bounded shear flows transitioning to turbulence may self-organize into alternating turbulent and laminar regions forming a stripe pattern with non-trivial oblique orientation. Different experiments and flow simulations identify oblique stripe patterns ...

Nature Research2019

Preferential Deposition of Snow and Dust Over Hills: Governing Processes and Relevant Scales

Marc Parlange, Michael Lehning, Marco Giovanni Giometto, Francesco Comola

Preferential deposition of snow and dust over complex terrain is responsible for a wide range of environmental processes and accounts for a significant source of uncertainty in the surface mass balances of cold and arid regions. Despite the growing body of ...

2019

Reduced Numerical Approximation of Reduced Fluid-Structure Interaction Problems With Applications in Hemodynamics

Simone Deparis, Claudia Maria Colciago

This paper deals with fast simulations of the hemodynamics in large arteries by considering a reduced model of the associated fluid-structure interaction problem, which in turn allows an additional reduction in terms of the numerical discretisation. The re ...

2018

Revisiting the quest for a universal log-law and the role of pressure gradient in "canonical" wall-bounded turbulent flows

Peter Monkewitz

The trinity of so-called "canonical" wall-bounded turbulent flows, comprising the zero pressure gradient turbulent boundary layer, abbreviated ZPG TBL, turbulent pipe flow, and channel/duct flows has continued to receive intense attention as new and more r ...

Amer Physical Soc2017

Basal entrainment by Newtonian gravity-driven flows

Nicolas Andreini, Christophe Ancey, Belinda Margaret Bates

Gravity-driven flows can erode the bed along which they descend and increase their mass by a factor of 10 or more. This process is called "basal entrainment." Although documented by field observations and laboratory experiments, it remains poorly understoo ...

Amer Inst Physics2016

Impact of rotating and fixed nozzles on vortex breakdown in compressible swirling jet flows

Leonhard Kleiser, François Gallaire

Vortex breakdown of swirling, round jet flows is investigated in the compressible, subsonic regime by means of Direct Numerical Simulation (DNS). This is achieved by solving the compressible Navier-Stokes equations on a cylindrical grid using high-order sp ...

Elsevier2016

Experimental and theoretical study of wind turbine wakes in yawed conditions

Fernando Porté Agel, Majid Bastankhah

This work is dedicated to systematically studying and predicting the wake characteristics of a yawed wind turbine immersed in a turbulent boundary layer. To achieve this goal, wind tunnel experiments were performed to characterize the wake of a horizontal- ...

Cambridge University Press2016

Discussion of "Skimming, Nonaerated Flow on Stepped Spillways over Roller Compacted Concrete Dams" by Ines Meireles, Floriana Renna, Jorge Matos, and Fabian Bombardelli

Michael Pfister

The nonaerated region may occupy a large portion of the skimming flow in steep, stepped spillways, particularly for relatively high unit flow rates. In spite of the numerous contributions on the hydraulic properties at both the inception point of air entra ...

American Society of Civil Engineers2014

An augmented mixed finite element method for the vorticity–velocity–pressure formulation of the Stokes equations

Ricardo Esteban Ruiz Baier

This paper deals with the numerical approximation of the stationary two-dimensional Stokes equations, formulated in terms of vorticity, velocity and pressure, with non-standard boundary conditions. Here, by introducing a Galerkin least-squares term, we end ...

Elsevier2013

On the stability of travelling waves with vorticity obtained by minimization

Boris Buffoni

We modify the approach of Burton and Toland Comm. Pure Appl. Math. LXIV. 975-1007 (2011) to show the existence of periodic surface water waves with vorticity in order that it becomes suited to a stability analysis. This is achieved by enlarging the functio ...

Springer Basel2013

Asymptotic-numerical derivation of the Robin type coupling conditions for the macroscopic pressure at a reservoir-capillaries interface

Alfio Quarteroni, Carlo D'Angelo

In this article the Stokes equations are considered in a domain simulating a capillary bed system. The capillaries are supposed to be thin, parallel and periodic. An asymptotic approximation is constructed. The macroscopic pressure satisfies a Robin interf ...

Taylor & Francis Ltd2013

Turbulent regimes in the tokamak scrape-off layer

Sébastien Jolliet, Joaquim Loizu Cisquella, Paolo Ricci, Annamaria Mosetto, Federico David Halpern

The non-linear turbulent regimes in the tokamak scrape-off layer (SOL) are identified according to the linear instability responsible for the perpendicular transport. Four regions of the SOL operational parameters are determined where turbulence is driven ...

American Institute of Physics2013

The influence of shear layer thickness on the stability of confined two-dimensional wakes

François Gallaire, Luca Biancofiore

The influence of confinement onto the inviscid and incompressible linear stability of the family of wakes introduced by Monkewitz [Phys. Fluids 31, 999 (1988)] is examined. The nondimensional parameters of the model, the velocity ratio Λ, defined as ratio ...

2011

Simulation of shear-driven flows : transition with a free surface and confined turbulence

Roland Bouffanais

The research work reported in the present dissertation is aimed at the analysis of complex physical phenomena involving instabilities and nonlinearities occurring in fluids through state-of-the-art numerical modeling. Solutions of intricate fluid physics p ...

EPFL2007

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

Steve Cochard, Sébastien Wiederseiner, Christophe Ancey, Martin Rentschler

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

A field study of turbulent flows in shallow gravel-bed rivers

Mário Jorge Rodrigues Pereira Da Franca

The study of turbulent flows has always been a challenge for scientists. Turbulent flows are common in nature and have an important role in several geophysical processes related to a variety of phenomena such as river morphology, landscape modeling, atmosp ...

EPFL2005

Simulation numérique des phénomènes thermiques et magnétohydrodynamiques dans une cellule de Hall-Héroult

Yasser Safa

This work is concerned with a numerical simulation of the thermal behaviour of an electrolysis cell for the production of the aluminium. Aluminium is produced by an electrolytic reduction of alumina dissolved in a bath of molten cryolite. In this reduction ...

EPFL2005