Sound transmission through cylindrical shell structures excited by boundary layer pressure fluctuations

Abstract

This paper examines sound transmission into two concentric cylindrical sandwich shells subject to turbulent flow on the exterior surface of the outer shell. The interior of the shells is filled with fluid medium and there is an airgap between the shells in the annular space. The description of the pressure field is based on the cross-spectral density formulation of Corcos, Maestrello, and Efimtsov models of the turbulent boundary layer. The classical thin shell theory and the first-order shear deformation theory are applied for the inner and outer shells, respectively. Modal expansion and the Galerkin approach are used to obtain closed-form solutions for the shell displacements and the radiation and transmission pressures in the cavities including both the annular space and the interior. The average spectral density of the structural responses and the transmitted interior pressures are expressed explicitly in terms of the summation of the cross-spectral density of generalized force induced by the boundary layer turbulence. The effects of acoustic and hydrodynamic coincidences on the spectral density are observed. Numerical examples are presented to illustrate the method for both subsonic and supersonic flows.

Sound transmission through double cylindrical shells lined with porous material under turbulent boundary layer excitation

“…The boundary conditions in the axial direction x at both ends were assumed to be simply supported [23,26,29,30] and can be expressed by…”

“…It is a double wall system which consists of a skin panel and a trim panel with an annular space between them. Therefore, Tang et al [29] studied the sound transmission into two concentric cylindrical sandwich shells subject to turbulent flow on the exterior surface of the outer shell. However, Tang et al [29] did not consider the effect of the porous lining in their study, which is widely used to control interior noise.…”

“…Therefore, Tang et al [29] studied the sound transmission into two concentric cylindrical sandwich shells subject to turbulent flow on the exterior surface of the outer shell. However, Tang et al [29] did not consider the effect of the porous lining in their study, which is widely used to control interior noise. Maury et al [30] studied the case of sound transmission through a flat double-panel, representative of an aircraft sidewall excited by a TBL.…”

“…Only few studies consider such geometry of the structure. Tang et al [26] used the modal expansion method and the Galerkin approach to develop an analytical model of sound transmission through cylindrical shell structures excited by a TBL. Rocha et al [27] developed an analytical model with closed-form expressions for the prediction of flow-induced noise in aircraft cylindrical cabins.…”

Modelling, system identification, and control of acoustic–structure dynamics in 3-D enclosures

“…An alternative derivation of 3-D rectangular acoustic enclosure is given in Pota (2001) which is easy to understand from a control design perspective. Modelling of acoustics in a two-layered cylindrical shell excited by a boundary layer pressure fluctuations was presented in Tang, Silcox, and Robinson (1996). Experimental results on control of acoustic radiation from structure (plate) were studied in Cox, Gibbs, Clark, and Vipperman (1998).…”