Seminar by Pedro Muradas

Coupling sonic black holes to a resonant cavity: numerical and experimental insights

Sonic black holes (SBHs) are usually composed of a waveguide with concentric rings of decreasing radius separated by cavities, which act to slow down incoming sound waves, dissipate their energy, and minimize reflections. While numerous studies have addressed SBH simulation methods, performance assessment, and design optimization, the interaction between SBHs and other acoustic systems has not yet been investigated. In this seminar, this interaction will be explored by analyzing the effect of coupling SBHs to a resonant cavity and examining their influence on the internal acoustic pressure field of that cavity. The patch transfer function (PTF) substructuring method is used to describe the complex coupled system. After validating the PTF methodology against full finite element simulations (FEM) of the coupled system, it is then used to perform parametric studies assessing the impact of both the number and the position of SBHs on the cavity’s mean quadratic pressure. Finally, recent experimental results of a cavity + SBH system are presented. Although SBHs are generally designed for medium- and high-frequency pressure attenuation in ducts, the results demonstrate that, with appropriate design, they can effectively dissipate low-frequency pressure peaks within a cavity. This suggests promising potential for applications such as room acoustics and other enclosed environments.