Parlons Sciences

Visit from Prof. Miguel ONORATO from the University of Torino, Italy, to talk to us about ..

Metareef: a device for attenuating surface gravity waves.

I have presented an experimental study on a device called Metareef, which consists of an array of submerged, inverted, and periodic cylindrical pendula (resonators) designed to attenuate surface gravity waves. This concept is inspired by metamaterials, engineered structures created to interact with waves and control their propagation.

The investigation is conducted in a wave flume, where waves are generated across a broad frequency range. Various configurations of the device are tested, and the transmitted, reflected, and dissipated wave energies are measured. When the frequencies of incoming waves are close to the natural frequency of the pendula, significant wave attenuation is observed, with the effect intensifying as the number of resonators increases. Additionally, the device demonstrates the ability to reflect energy at specific incoming wave frequencies, governed by a generalized Bragg scattering mechanism that depends on the spacing between the resonators.

The results highlight the potential of Metareef as an environmentally sustainable solution for mitigating wave impacts in coastal areas.