Negative refraction of deep water waves through water channel network

Abstract

A design method of a negative refractive index for free surface water waves in deep water is presented. To obtain a condition of a negative index, an analogy between water waves in a water channel and electric waves in an electric circuit. An analytical solution of waves around a periodic array of rectangular columns is obtained by a circuit analysis. Attention is not focused on columns but a space among columns, and then the space is regarded as the water channel. Therefore, the circuit analysis can be applied to water waves. One channel is treated as a unit structure and a number of channels are periodically cascaded as a network. The negative refraction and backward waves by a network of the water channels are shown. Since the negative refraction might occur even around simple periodic structures, it is meaningful to understand wave phenomenon around offshore structures and develop innovative technology.