Two-dimensional underwater acoustic cloakinging and simulationan- A practically-feasible design

A two-dimensional underwater acoustic cloak (UAC) is designed and simulated considering the fabrication processes limitations. UAC microstructure includes pentamode materials and their geometrical dimensions are obtained through an optimization procedure using COM-SOL-MATLAB Live Link. First, a random data is generated for the UAC microstructure; then, its dispersion curve is extracted in COMSOL Multiphysics software. Next, the phase speeds and effective density, bulk and shear moduli are obtained in MATLAB software. Af-terwards, the effective properties are compared with the desired values determined from the transformation-based acoustic cloaking theory. A constant-density transformation function is taken into account. Finally, an optimized microstructure is acquired for UAC with dimen-sions practically feasible for fabrication. Then, UAC is simulated in COMSOL Multiphysics under an acoustic incident wave for the cloaking performance assessment. A circular object with and without cloak is taken into account in a two-dimensional water domain with an acoustic incoming wave. The total and scattered pressure field contours show that the de-signed UAC can considerably decrease the scattered waves and thus the reflected waves are significantly reduced which leads to the object target strength reduction.

کلیدواژه ها:

Acoustic cloaking ، Pentamode materials ، Optimization ، COMSOL.