Research on the parametric array's acoustic characteristics in layered medium

The parametric array can eradiate high directivity, low frequency beams with a small aperture, so it has gained wide attention in underwater acoustic engineering. Meanwhile, the parametric array's conversion efficiency is very low, severely restrict the parametric array's further application. In order to improve the conversion efficiency, this report used the KZK equation to calculate the parametric array's acoustic characteristics in the layered medium. Results showed that the maximum values of the difference wave always appeared at the junction of the layered medium, and the layered medium with larger nonlinear parameter, smaller velocity and lower attenuation coefficient has a larger conversion efficiency. The report may provide theoretical guidance for the parametric array's future applications.