Research on the parametric array sound characteristic of the annular transducer

The parametric array can generate low-frequency, high-directivity beam with small-aperture, and it is widely used in underwater navigation, underwater communication, seafloor sediments detection, sub-bottom physiognomy surveying and mapping. However, the parametric array´s conversion efficiency is very low, severely restricting the parametric array´s further application. In order to improve the parametric array´s conversion efficiency, the paper combined the backward implicit finite difference(IBFD) method and Crank-Nicolson finite difference(CNFD) method to solve the KZK equation. We also studied the parametric array´s nonlinear sound field of the annular transducer, and compared the parametric array´s sound fields of the circular transducer with the same radiation area. The simulation results showed that the annular transducer could also generate low frequency sound beam with high directivity, and the annular transducer source has a slightly higher difference frequency sound pressure amplitude.