Vibro-acoustic modeling to study the acoustic scattering by elastic objects under a free surface
The SURCOUF ANR project investigates the effects of the sea surface on the acoustic radiation and scattering of resonant objects immersed at relatively shallow depths. The objects considered, representative of a naval structure, are stiffened cylindrical hulls limited by flanges or hemispherical caps. The main aim of this project is to evaluate experimentally and numerically the influence of the free surface on the acoustic signatures of these hulls for different immersion depths, by distinguishing between the acoustic contributions induced by the proximity of the free surface and those linked to the object’s own response. This project is part of a collaboration between the vibrations-acoustics laboratory (LVA) at INSA Lyon, the waves and complex media laboratory (LOMC) at the University of Le Havre, and the industrial company NAVAL-Group.
The position at LVA of INSA Lyon focuses on vibro-acoustic modeling. The first step will be to develop an analytical model of a periodically stiffened shell of infinite lateral extension immersed beneath a free surface. The effects of the free surface on Bragg and Bloch-Floquet scattering will then be demonstrated. Secondly, we will focus on finite-dimensional shells, using the concept of « condensed transfer functions » developed in the laboratory. The numerical results will be compared with water tank measurements carried out at LOMC. This work could also be the subject of a collaboration with an Australian team working on the same theme (UTS, University of Technology, Sydney). The work carried out will be published in peer-reviewed journals (JSV, JASA).
More informations on the link below.