Personne
Edouard Boujo
Publications associées (32)
Second-order sensitivity in the cylinder wake: Optimal spanwise-periodic wall actuation and wall deformation
François Gallaire, Edouard Boujo, Andrea Fani
Two-dimensional (2D) flows can be controlled efficiently using spanwise "waviness," i.e., a control (e.g., wall blowing and suction or wall deformation) that is periodic in the spanwise direction. This study tackles the global linear stability of 2D flows ...
AMER PHYSICAL SOC2019Revisiting the drag reduction problem using adjoint-based distributed forcing of laminar and turbulent flows over a circular cylinder
François Gallaire, Edouard Boujo, Philippe Meliga
This study assesses the ability of a sensitivity-based, span-wise homogeneous control velocity distributed at the surface of a circular cylinder to cut down the cost of reducing drag by more classical techniques, e.g., base bleed and lateral suction. At Re ...
ELSEVIER SCIENCE BV2018Numerical simulation and sensitivity analysis of a low-Reynolds-number flow around a square cylinder controlled using plasma actuators
François Gallaire, Edouard Boujo, Philippe Meliga
Flow around a square cylinder controlled using plasma actuators (PAs) is numerically investigated by direct numerical simulation in order to clarify the most effective location of actuator installation and to elucidate the mechanism of control effect. The ...
Amer Physical Soc2017A self-consistent formulation for the sensitivity analysis of finite-amplitude vortex shedding in the cylinder wake
François Gallaire, Edouard Boujo, Philippe Meliga
We use the adjoint method to compute sensitivity maps for the limit-cycle frequency and amplitude of the Benard von Karmzin vortex street in the wake of a circular cylinder. rfhe sensitivity, analysis is performed in the frame of the semi-linear self consi ...
Cambridge University Press2016Pushing amplitude equations far from threshold: application to the supercritical Hopf bifurcation in the cylinder wake
François Gallaire, Edouard Boujo, Philippe Meliga, Cristobal Manuel Arratia Martinez, Vladislav Mantic Lugo
The purpose of this review article is to push amplitude equations as far as possible from threshold. We focus on the Stuart-Landau amplitude equation describing the supercritical Hopf bifurcation of the flow in the wake of a cylinder for critical Reynolds ...
Iop Publishing Ltd2016Sensitivity and open-loop control of stochastic response in a noise amplifier flow: the backward-facing step
François Gallaire, Edouard Boujo
The two-dimensional backward-facing step flow is a canonical example of noise amplifier flow: global linear stability analysis predicts that it is stable, but perturbations can undergo large amplification in space and time as a result of non-normal effects ...
Cambridge University Press2015Second-order sensitivity of parallel shear flows and optimal spanwise-periodic flow modifications
François Gallaire, Edouard Boujo, Andrea Fani
The question of optimal spanwise-periodic modification for the stabilisation of spanwise-invariant flows is addressed. A second-order sensitivity analysis is conducted for the linear temporal stability of parallel flows U-0 subject to small-amplitude spanw ...
Cambridge University Press2015An adjoint-based approach to the optimal control of separated flows
Flow separation is relevant to many industrial applications, since it is detrimental to the aerodynamic performance of vehicles, induces vibrations in mechanical structures, but can also contribute to improve mixing in combustion devices. In this thesis, t ...
EPFL2014Controlled reattachment in separated flows: a variational approach to recirculation length reduction
François Gallaire, Edouard Boujo
A variational technique is used to derive analytical expressions for the sensitivity of recirculation length to steady forcing in separated flows. Linear sensitivity analysis is applied to the two-dimensional steady flow past a circular cylinder for Reynol ...
Cambridge University Press2014Open-loop control of a separated boundary layer
François Gallaire, Edouard Boujo
Linear optimal gains are computed for the separated boundary-layer flow past a two-dimensional bump in the subcritical regime. Very large values are found, making it possible for small-amplitude noise to be strongly amplified and to desta ...
Elsevier France-Editions Scientifiques Medicales Elsevier2014