Publications associées à Flot (mathématiques)

The Strong Integral Input-to-State Stability Property in Dynamical Flow Networks

Dynamical flow networks serve as macroscopic models for, e.g., transportation networks, queuing networks, and distribution networks. While the flow dynamics in such networks follow the conservation of mass on the links, the outflow from each link is often ...

Ieee-Inst Electrical Electronics Engineers Inc2024

Stability: a search for structure

Wouter Jongeneel

In this thesis we study stability from several viewpoints. After covering the practical importance, the rich history and the ever-growing list of manifestations of stability, we study the following. (i) (Statistical identification of stable dynamical syste ...

EPFL2024

Scalable Computation of Dynamic Flow Problems via Multimarginal Graph-Structured Optimal Transport

Isabel Haasler, Axel Ringh, Yiqiang Chen

In this work, we develop a new framework for dynamic network flow pro-blems based on optimal transport theory. We show that the dynamic multicommodity minimum-cost network flow problem can be formulated as a multimarginal optimal transport problem, where t ...

2023

Temporal and spatial evolution of cavitating bubbles and coherent structures in a confined submerged jet shear layer

Sebastián Camilo Leguizamón Sarmiento, Yuchuan Wang

Purpose The study aims to display the bubbles' evolution in the shear layer and their relationship with the pressure fluctuations. Furthermore, the coherent structures of the first six modes are extracted, in order to provide insight into their temporal an ...

EMERALD GROUP PUBLISHING LTD2021

Distinctive features of horizontal and vertical velocity profiles in turbidity and saline density currents

Giovanni De Cesare, Sara Venuleo, Shun Nomura, Jumpei Hitomi

The flow field of turbidity current and saline density current in lock-gate flume is measured by the ultra-sound Doppler velocity profiler. The horizontal and vertical velocity and their fluctuations are discussed. ...

2018

Unsteady fluid dynamics around a hovering flat plate wing

Swathi Badala Krishna

Insect flight is characterised by complex time-dependent flows in response to the unsteady wing movements. Biological fliers exploit the unsteady flow fields to modulate aerodynamic forces, thereby displaying unmatched flight performance, especially in hov ...

EPFL2017

Bifurcation Dynamics of a Particle-Encapsulating Droplet in Shear Flow

François Gallaire, Lailai Zhu

To understand the behavior of composite fluid particles such as nucleated cells and double emulsions in flow, we study a finite-size particle encapsulated in a deforming droplet under shear flow as a model system. In addition to its concentric particle-dro ...

American Physical Society2017

Self-consistent model for the saturation mechanism of the response to harmonic forcing in the backward-facing step flow

François Gallaire, Vladislav Mantic Lugo

Certain flows denominated as amplifiers arc characterized by their global linear stability while showing large linear amplifications to sustained perturbations. As the forcing amplitude increases, a strong saturation of the response appears when compared t ...

Cambridge University Press2016

Experimental study on the influence of abrupt slope changes on flow characteristics over stepped spillways

Mohammad Javad Ostad Mirza

Application of stepped spillways increases the energy dissipation rate along the spillway and may reduce the dimensions of the terminal energy dissipation structure. This pronounced energy dissipation makes stepped chutes attractive under various condition ...

EPFL2016

Too big to grow : self-consistent model for nonlinear saturation in open shear flows

Vladislav Mantic Lugo

Open flows, such as wakes, jets, separation bubbles, mixing layers, boundary layers, etc., develop in domains where fluid particles are continuously advected downstream. They are encountered in a wide variety of situations, ranging from nature to technolog ...

EPFL2015

Dynamics of isolated confined air bubbles in liquid flows through circular microchannels: an experimental and numerical study

John Richard Thome, Navid Borhani, Mirco Magnini, Sepideh Khodaparast

Experimental and numerical studies are performed to characterise the dynamics of isolated confined air bubbles in laminar fully developed liquid flows within channels of diameters d = 0.5 mm and d = 1 mm. Water and glycerol are used as the continuous liqui ...

Springer Verlag2015

Turbulent scale resolving modelling of rotating stall in low-pressure steam turbines operated under low volume flow conditions

Peter Ott, Benjamin Megerle, Ivan William McBean

Non-synchronous excitation under low volume operation is a major risk to the mechanical integrity of last stage moving blades (LSMBs) in low-pressure (LP) steam turbines. These vibrations are often induced by a rotating aerodynamic instability similar to r ...

2015

Improved Variational Denoising of Flow Fields with Application to Phase-Contrast MRI Data

Michaël Unser, Nikolaos Stergiopoulos, Emrah Bostan, Orestis Vardoulis, Stamatios Lefkimmiatis

We propose a new variational framework for the problem of reconstructing flow fields from noisy measurements. The formalism is based on regularizers penalizing the singular values of the Jacobian of the field. Specifically, we rely on the nuclear norm. Our ...

IEEE Institute of Electrical and Electronics Engineers2015

Thermal-diffusive instabilities in unstretched, planar diffusion flames

Peter Monkewitz, Etienne Robert

The recent development of a novel research burner at EPFL has opened the way for experimental investigations of essentially unstretched planar diffusion flames. In particular, it has become feasible to experimentally validate theoretical models for thermal ...

Elsevier2012

Invariant Measures of Gaussian Type for 2D Turbulence

Gaussian measures μβ,ν are associated to some stochastic 2D models of turbulence.They are Gibbs measures constructed by means of an invariant quantity of the system depending on some parameter β (related to the 2D nature of the fluid) and the viscosity ν.W ...

Springer2012

Variational Enhancement And Denoising Of Flow Field Images

Michaël Unser, Ricard Delgado Gonzalo, Pouya Dehghani Tafti

In this work we propose a variational reconstruction algorithm for enhancement and denoising of flow fields that is reminiscent of total-variation (TV) regularization used in image processing, but which also takes into account physical properties of flow s ...

Ieee Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2011

Experimental study of velocity fields in rectangular shallow reservoirs

Anton Schleiss, Erica Camnasio

Velocity fields in rectangular shallow reservoirs with different length-to-width and expansion ratios were investigated in an experimental study, to evaluate the effect of geometry on the flow field. A wide range of combinations of these two non-dimensiona ...

Taylor & Francis Ltd2011

Towards oscillation-free implementation of the immersed boundary method with spectral-like methods

Jiannong Fang, Marc Parlange, Chad Higgins, Marc Diebold

It is known that, when the immersed boundary method (IBM) is implemented within spectral-like methods, the Gibbs oscillation seriously deteriorates the calculation of derivatives near the body surface. In this paper, a radial basis function (RBF) based smo ...

Elsevier2011

Fractal Modelling And Analysis Of Flow-Field Images

Michaël Unser, Ricard Delgado Gonzalo, Pouya Dehghani Tafti

We introduce stochastic models for flow fields with parameters that dictate the scale-dependent (self-similar) character of the field and control the balance between its rotational vs compressive behaviour. The development of our models is motivated by the ...

Ieee Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2010

Experimental investigation of unstrained diffusion flames and their instabilities

Etienne Robert

In this thesis, thermal-diffusive instabilities are studied experimentally in diffusion flames. The novel species injector of a recently developed research burner, consisting of an array of hypodermic needles, which allows to produce quasi one-dimensional ...

EPFL2009