Skip to Main content Skip to Navigation
Theses

Contrôle des perturbations aéroacoustiques par impédances de parois : application à un modèle de matériaux poreux

Abstract : To reduce the noise out of an engine nozzle, the acoustic treatments must be realizable by materials adapted to aeronautic constraints and characterized by adjustable complex impedances.
The purpose of this thesis is the study and the control of a model of aero-acoustic disturbances of a stationary and subsonic initial flow, the system governed by the linearized Euler equations (LEE). The goal is to control the phenomena of aero-acoustic propagations, generated in a field (a priori infinite) and located on a space-time observatory, by using as control variables the local parameters of complex impedances characterizing the boundary of a solid obstacle located inside the field. We show that the LEE system constitutes a Friedrichs' system for which one classifies in an exhaustive way the boundary conditions, which return an well-posed increased system (called direct problem) on a bounded time-space domain. From this study naturally rises a well-posed adjoint problem, which is an essential step to the resolution of inverse problems.
The numerical method chosen to approximate these problems is a Galerkin discontinuous one with an upwind flux-splitting in space, combined with a Runge-Kutta scheme in time. As always in wave propagations, absorbing boundary conditions are of primary importance. Accordingly, a PML method adapted to the LEE is proposed and numerically validated.
Lastly, a very detailed attention is paid to the physical meaning of this work. An homogeneized model of porous material is used, making it possible to connect the control variables to physical parameters characterizing the experimental feasibility of absorbent materials. The numerical results obtained with an academic model of air intake, illustrate the efficiency of this methodology to solve aero-acoustic inverse problems with their complexities.
Complete list of metadatas

https://tel.archives-ouvertes.fr/tel-00136437
Contributor : Yoann Ventribout <>
Submitted on : Wednesday, March 14, 2007 - 8:09:06 AM
Last modification on : Friday, June 26, 2020 - 2:00:02 PM
Long-term archiving on: : Wednesday, April 7, 2010 - 1:34:12 AM

Identifiers

  • HAL Id : tel-00136437, version 1

Collections

Citation

Yoann Ventribout. Contrôle des perturbations aéroacoustiques par impédances de parois : application à un modèle de matériaux poreux. Modélisation et simulation. Ecole nationale superieure de l'aeronautique et de l'espace, 2006. Français. ⟨tel-00136437⟩

Share

Metrics

Record views

418

Files downloads

225