Thermo-Acoustic Effects on the Natural Frequencies of Vibration of an Elastic Rectangular Panel

Abstract

In this paper, the thermo-acoustic behaviour of a rectangular panel fully immersed in a compressible fluid at rest is investigated. A boundary element method BEM has been employed taking into account the Kirchhoff-Helmholtz K-H integral equation for the acoustic pressure and with the fluid-plate interface boundary condition the acoustic pressure jump over the panel is calculated. The thermal effects are considered regarding in the form of a uniform increment of temperature of the panel and are analysed in order to prevent the buckling phenomena. The deformation modes of the panel correspond to the vacuum case. Applying a collocation method for the panel equation, the natural frequencies are obtained . The effect of several geometric parameters regarding different thermal loads, on these frequencies are evaluated. Furthermore, the influence of the wave number for different temperatures of the panel on the acoustic damping ratio is evaluated, as well as the acoustic radiation efficiency for the different modes. The verification of the method is proven with other works.