Contribution
Design of acoustic sound absorbers
* Presenting author
Abstract:
Acoustic metamaterials have the potential to reduce vibration and noise in a targeted and narrow band of frequencies. The main concepts are based on mechanical resonators that act as vibration absorbers at their natural frequency, absorbing energy that would otherwise be emitted as airborne sound and perceived as noise. Metamaterials that exploit this mechanism are called locally resonant acoustic metamaterials (LRAM). The locally resonant structures are periodically attached to the baseplate. However, the question arises whether the periodic arrangement is necessary. Furthermore, spiral acoustic black holes can be used instead of local resonant structures. Therefore, we use numerical simulations to investigate a test structure and compute the mechanical as well as the acoustic intensity of the baseplate to find optimised positions for the local resonant structures as well as the spiral acoustic black holes. In doing so, we are demonstrating the potential of broadband absorbers with reduced manufacturing effort.