Analysis of the external radiation from circular cylindrical shells

作者：Aslani Pegah^*; Sommerfeldt Scott D; Blotter Jonathan D

来源：Journal of Sound and Vibration, 2017, 408: 154-167.

DOI：10.1016/j.jsv.2017.07.021

• Radiation mode shapes
• Cylindrical shell
• Acoustic basis functions
• Cut-on phenomena

Structurally radiated sound power is a critical design parameter. The acoustic radiation mode approach for computing sound power was developed in the early 1990s and has since been widely used. It has been shown to be a rather efficient approach for determining the radiated sound power. In previous research, radiation mode expressions have been developed for planar and spherical structures, as well as axisymmetric modes of internal and external radiation from cylinders. In this work, the radiation modes for external radiating cylinders which account for both axial and circumferential dependence are presented. The expressions are uniquely developed using cylindrical basis functions which are a more natural match to the geometry than past developments, which have been based on spherical harmonics. Higher order radiation modes than have been previously presented are shown. The leapfrog effect, whereby higher order modes leapfrog over lower modes in terms of their radiation efficiencies as the frequency goes above the cut-on frequency for those modes, is discussed in detail. The relationships between the mode efficiency and the coincidence effect associated with the cut-on frequencies of the vibration modes are described.

• 出版日期2017-11-10