Development of novel, light-weight and multifunctional acoustic metamaterials/metasurfaces for aeronautical applications

The work presented is focused on modelling and testing the already existing metamaterials and metasurfaces in an aeroacoustics environment and modifying them to enhance their performance in mean flow. Metamaterials and metasurfaces can exhibit nearly arbitrary values of effective density and modulus, which may be manipulated to modify acoustic effects for noise control. Basically, the idea is to develop a hybrid three-layer metamaterial/metasurface, which consists of ribbed like structure to concentrate acoustic energy (top layer) [2], a GRaded INdex Sonic Crystal for redirecting the acoustics waves (middle layer) [6] and resonant based acoustics cavities to dissipate and absorb acoustic energy (bottom layer) [7]. In proposed design, the first layer will act like lens for energy concentration, and then redirecting the energy away from the receiver may reduce the impact of noise generated by aircraft and a third layer of metamaterials be added for acoustics energy absorption and dissipation.