浅水波における負の屈折率を実現する水路網に関する研究

抄録

In this paper, the water wave metamaterial is studied to realize the negative refractive index. Shallow water waves propagating to the water channel are analogized to electric waves flowing through the distributed constant circuit, and thus the circuit theory based approach is extended to water waves. We propose the design method of the water channel that characteristics of both inductance- and capacitance- equivalents are negative. We also derive that the refractive index and the phase velocity become negative values at that time. Water channels are periodically cascaded and consequently, the water channel network is constructed. The water channel network acts as the water wave metamaterial. The proposed theory is validated by the numerical computation and there is a good agreement between them. The numerical simulation shows that waves incident to the water channel network are refracted at the negative angle and the phase velocity propagates against the group velocity, that is, backward waves are observed.