Numerical investigation on the effect of structure parameter of acoustic field rotator on its operating bandwidth

Abstract

The theory about transformation acoustics is introduced to indicate that designing an acoustic field rotator, in reality, is feasible. Then, numerical research is conducted to investigate the effect of geometrical parameters on the high cut-off frequency, including the size of building block, the aspect ratio of building block, the size of acoustic field rotator, the external diameter of acoustic field rotator, and the internal diameter of acoustic field rotator. The results suggest that the sizes of building blocks of acoustic field rotators are inversely proportional to their high cut-off frequencies in the studied frequencies. The effect of the size of acoustic field rotator mainly lies in the size of building block instead of the number of the building block. There is a linear relationship between the aspect ratio of the building block and high cut-off frequency in the studied frequencies. In addition, the layer of building block has an effect on high cut-off frequency as well. The current numerical study is helpful to give a better guidance for designing the acoustic field rotator.