In this paper, analytical solutions are used to compute the acoustic insulation provided by plane and circular closed walls when subjected to sinusoidal harmonic line pressure loads. In the first case the panel is assumed to have infinite extent and the pressure wave field is computed using 2.5D Green's functions established in Cartesian co-ordinates for an infinite solid layer bounded by fluid media. The three-dimensional problem is formulated as a summation of two-dimensional problems for different wave numbers along the z direction. Each two-dimensional problem in turn is written as a superposition of plane waves for varying wave numbers along the x direction. The curved wall is modelled as a cylindrical solid annulus bounded by fluid media, and the pressure wave field is computed using analytical expressions expressed in cylindrical co-ordinates. The three-dimensional problem is likewise broken down into a set of two-dimensional problems, with different wave numbers along the z direction. The influence of the curvature of the wall on the results is studied by comparing the responses of both models where the thickness is the same, but the radius of the annulus varies. The assumption of a circular closed wall allows the vibration modes of the enclosure to be found, and makes it possible to assess the influence of this phenomenon on the sound insulation.
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