Synthesis of wall pressure fields of non-homogeneous turbulent boundary layers for vibroacoustic simulations.

Abstract

In this paper, a numerical process is presented for predicting the response of vibrating structures excited by a non-homogeneous turbulent boundary layer. This one is based on the synthesis of different realizations of the random pressure fluctuations that can be introduced as loading of a vibroacoustic model. The vibratory response is finally deduced by averaging together the responses of the different loads. As a first approach, the pressure fluctuations of the non-homogeneous turbulent boundary layer can be generated separately for different sub-areas of the structure by using the uncorrelated wall plane waves technique and mean boundary layer parameters. An extension of this basic approach consists in taking into account the interaction between the sub-areas and a refinement of the sub-area decomposition. Wall pressure fluctuations related to a continuous evolution of the boundary layer can then be generated and introduced in the vibroacoustic model. The accuracy of the proposed approach is studied on a rectangular panel excited on one side by a growing fully turbulent boundary layer triggered at one edge of the plate. Comparisons with the spatial approach and the wavenumber approach using the sub-area decomposition technique are proposed. Interests of the proposed approach in terms of accuracy and computing times are discussed.