Vibration damping of thin structures using surface-attached spiral acoustic black holes

Vibration damping or noise reduction can be achieved by using an acoustic black hole (ABH) that is a wedge-shaped structure with power-law thickness. Recently, a spiral ABH was reported to reduce occupied space by the ABH. In this study, we proposed a surface-attached spiral acoustic black hole (ABH) to reduce not only the space but also the weight of the ABH while maintaining its damping performance. Numerical results show that the surface-attached spiral ABH can significantly reduce the mobility peaks of a reference structure up to 31.3 dB in the frequency range below 500 Hz. When compared to a previous technique for vibration damping, the proposed spiral ABH is much lighter and compacter, indicating that the surface-attached spiral ABH can be an effective, compact, and light-weight solution for vibration damping.