Modeling, optimization, design and control of piezoelectric loudspeakers
Dielectric elastomer loudspeakers are thin soft membranes inflated over a closed cavity. Soft electrodes are put on each side of the membrane, which deforms and produces sound when strong electrical fields are then imposed.
We need to rethink our modes of transportation. Airships may play a role again in the years to come. In this context, we are interested in the modeling and prediction of aerodynamic forces on light structures of this type...
Whether it is the sound of musical instruments or urban noises, we often need to achieve sound synthesis (modern music production, decision-making support for policy makers, etc.). In this work, we base ourselves on physical models to achieve realistic and configurable sound syntheses.
Fluid-conveying pipe flutter, flag flutter, instabilities of slender industrial structures...
Flutter instability induces an energy transfer flow a flow to a structure that we investigated theoretically, numerically and experimentally. We showed how and why efficiency can be maximized.
Shape memory alloy are complex materials that are subject to solid-solid phase changes, which induce many different behaviours. In this project we propose to take profit of the loop that can occurs in these materials to dissipate energy and mitigate resonant oscillations. We carried out the first experimental demonstration of the hysteresis due to the softening effect of the dissipative loop.
In this course the coupled fluid and solid equations are derived. The dimensionnal analysis is presented. Main phenomena that occur when a structure is coupled to a fluid are then presented : added mass, stiffness, damping, bluckling and flutter instabilities, vortex induced vibrations, etc.
I initially created this course for my students at ENSTA-Paris : MS205
It is now proposed also at Ecole Polytechnique , and at Centrale Supélec.
Videos (in french) cover all the lectures. Please visit my page dedicated to this course : Cours d'interaction fluide-structure
The main objective of this introductory acoustics course is to provide the theoretical and practical elements necessary for the calculation of sound fields in fluid media and the processing of acoustic signals.
In addition to tutorials, a room acoustics project is proposed, consisting of carrying out measurements in the classroom, then using the data to study the influence of acoustic elements on reverberation times. We also create artificial reverberations from the data collected.
The objective of this course is to provide the basics of experimental methods in mechanics. Several fields of mechanics are covered: fluid mechanics, solid mechanics, and vibrations.
The first part of the course is mainly made up of lectures that will deal with the physics and the use of the main sensors in each field, and with the notions of signal acquisition and processing.
In a second part, experimental projects are proposed in solid mechanics, fluid-mechanics and vibrations.
Lecture slides on energy harvesting from oscillatory instabilities in fluid-structure interaction, at the FDSE summer school (July 2017, July 2019), at Tonnerres de Brest 2012 (July 2012):
Lecture notes on the dissipation effect on aeroelastic instabilities and energy harvesting, at the CIM summer school (Udine, April 2017):
Download lecture notes
(published as a book chapter )