Space–coiling metamaterials that exploit the generalized Snell’s law are suitable for the subwavelength manipulation of acoustic waves, leading to extraordinary refraction and reflection properties. Typically, space–coiling metasurfaces are characterized by a narrow operating range in frequency due to the intrinsic connection between the design wavelength and the characteristic dimensions of the metasurface. The main goal of the present work is to design a broadband and modular metasurface based on space–coiling cells by extending the range of frequency where the effective metabehaviour is achieved through numerical optimization. The metasurface module is composed by eight different unit cells, each introducing a tailored phase shift in the field, that can be combined side by side to produce the desired acoustic effect. The design parameters of each cell are selected as the result of an optimization process that minimizes the dependency on the operating frequency of the metabehaviour, keeping the overall thickness below a quarter of the design wavelength. Preliminary results are obtained for a benchmark problem.
Palma, G., Centracchio, F., Burghignoli, L., Iemma, U., Cioffi, I. (2019). Steering of acoustic reflection from metasurfaces through numerical optimization. In 25th AIAA/CEAS Aeroacoustics Conference, 2019. American Institute of Aeronautics and Astronautics Inc, AIAA [10.2514/6.2019-2559].
Steering of acoustic reflection from metasurfaces through numerical optimization
Palma G.
;Centracchio F.;Burghignoli L.;Iemma U.;Cioffi I.
2019-01-01
Abstract
Space–coiling metamaterials that exploit the generalized Snell’s law are suitable for the subwavelength manipulation of acoustic waves, leading to extraordinary refraction and reflection properties. Typically, space–coiling metasurfaces are characterized by a narrow operating range in frequency due to the intrinsic connection between the design wavelength and the characteristic dimensions of the metasurface. The main goal of the present work is to design a broadband and modular metasurface based on space–coiling cells by extending the range of frequency where the effective metabehaviour is achieved through numerical optimization. The metasurface module is composed by eight different unit cells, each introducing a tailored phase shift in the field, that can be combined side by side to produce the desired acoustic effect. The design parameters of each cell are selected as the result of an optimization process that minimizes the dependency on the operating frequency of the metabehaviour, keeping the overall thickness below a quarter of the design wavelength. Preliminary results are obtained for a benchmark problem.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
