Attenuating surface gravity waves using concepts from metamaterials
Abstract
I will report on an experimental study of a device composed of an array of submerged, reversed and periodic cylindrical pendula (resonators), whose objective is the attenuation of surface gravity waves. The idea is inspired by the concept of metamaterials, i.e. engineered structures designed to interact with waves and manipulate their propagation properties. The study is performed in a wave flume where single frequency waves are excited in a wide range of frequencies. We explore various configurations of the device, measuring the transmitted, reflected and dissipated energy of the waves. If the incoming wave frequencies are sufficiently close to the natural frequency of the pendula, we find a considerable wave attenuation effect, driven by viscous dissipative mechanisms. This behaviour is enhanced by the number of resonators in the array. Moreover, the device is also capable of reflecting the energy of selected frequencies of the incoming waves. The presented results show promise for the development of an environmentally sustainable device for mitigating waves in coastal zones.
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