A hybrid patch transfer-Green functions method to solve transmission loss problems of flat single and double walls with attached sound packages

This paper presents and studies the performance of a sub-structuring method that employs a patch transfer approach (PTF) to couple the standard finite element schemes of the structures and cavities with an analytical model of the sound package. First, the approach is presented followed by a convergence study to define a patch mesh criterion. Then, the accuracy of the proposed methodology is assessed for single and double wall transmission problems with two different attached noise control treatments. The obtained results are systematically compared to three models, namely full finite element/boundary element strategies (FEM/BEM), and to two sub-structuring approaches based on the modeling of the sound package by (i) a locally reacting model and (ii) FEM. It is observed that the proposed method predict accurately and efficiently the dynamic behavior of flat trimmed vibroacoustic systems.