381 / 2022-01-25 15:40:45

A Parametric Study of Wave Energy Dissipation in Eccentric Acoustic Black Hole Indentations

Acoustic Black Hole,Eccentric design,Flexural wave focalization,Energy dissipation

Vibro-acoustics and Structure-borne Noise

The drastic flexural wave focalization and dissipation effect in Acoustic Black Hole (ABH) indentations has widely attracted attentions. Motivated by the phenomenon we have found in our previous work, the position of the energy focalization is offset from the centre in general imperfect ABH indentations, an eccentric ABH indentation is proposed in this work. The central plateau offset from the centre is designed to enhance the wave focalization effect, which ensures that the flexural waves are accumulated onto it. The thickness profile of any circumferential cross section satisfies the polynomial function of a general imperfect ABH indentation. Numerical models of the ABH indentations are built and assembled using finite element method. Based on numerical results, the power flow analysis is conducted for quantitative evaluation of energy focalization. Damping layer is applied on the surface of the central plateau to dissipate the focused wave energy. The influence of the offset distance on both energy focalization and dissipation is investigated. Results demonstrate that the there is an optimal offset distance in the eccentric ABH Indentations when the minimum thickness is constant. Comparing to the conventional ABH indentations, the efficiency of wave energy dissipation is improved by the eccentric design.