On the modeling of the diffuse field sound transmission loss of finite thickness apertures.
The modeling of the diffuse field sound transmission loss (TL) of apertures has been rarely considered in the literature. The aims of this paper are (i) to give a comprehensive review of the existing models, (ii) to propose a general efficient and rigorous numerical method to predict the diffuse field TL of apertures of rectangular and circular cross section, (iii) to provide the reader with numerical results regarding this indicator together with its relation with the normal incidence case for various geometrical configurations, and (iv) to conclude on the relevance of using such a sophisticated model compared to more classical normal incidence ones. The proposed approach is based on the description of the sound field inside the aperture in terms of propagating and evanescent acoustic modes. The radiation of the aperture is accounted for using a modal radiation impedance matrix. The coupled problem is solved in terms of modal contribution factors. The convergence of the approach is then investigated and the model is validated by comparisons with existing models for various configurations and excitations. Several numerical examples are provided regarding the normal incidence and diffuse field TL for various apertures and the relationship between these two indicators is discussed.
Sgard
Franck
F
Laboratoire des Sciences de l'Habitat, DGCB URA CNRS 1652, Ecole Nationale des Travaux Publics de l'Etat, Vaulx-en-Velin Cedex, France. frasga@irsst.qc.ca
Nelisse
Hugues
H
Atalla
Noureddine
N
D003198:Computer Simulation; D004058:Diffusion; D017097:Electric Impedance; D008962:Models, Theoretical; D009038:Motion; D011312:Pressure; D015203:Reproducibility of Results; D013016:Sound; D014732:Vibration