Vibroacoustic subtractive modelling: Principle of the reverse condensed transfer function approach and application to the prediction of the noise radiated by a partially coated cylindrical shell

Abstract

Substructuring methods are commonly used to solve vibroacoustic problems, as they allow studying complex systems by dividing them into smaller subsystems that can be studied separately. If they are generally used to couple subsystems, we are interested here in the decoupling procedure, consisting in subtracting a subsystem from a global system. Decoupling procedures can be used to perturbate an existing model in order to investigate the impact of a default on a given system, or to study problems with complex geometries, starting from a canonical system. In the framework of subtractive modelling, the reverse condensed transfer function (rCTF) method has been developed to decouple vibroacoustical subsystems that are initially coupled along lines or surfaces. The aim of this approach is to predict the response at any point of the final decoupled subsystem. The method will be presented on an academic test case consisting in the scattering problem of a plane wave by a rigid sphere immersed in an infinite water medium. Then, an example of industrial application will be proposed by studying the acoustic radiation of a partially coated cylindrical shell using the rCTF method.