Study of the acoustic nonlinear field generated from a phased array using Gaussian superposition technique

A numerical approach is developed to calculate the nonlinear sound field generated from a phased array based on the superposition technique of Gaussian beams.The parameters of the phased array elements are first estimated from the focal parameters using the inverse matrix algorithm;Then the elements are expressed as a set of Gaussian functions; Finally,the nonlinear sound field can be calculated using the superposition technique of Gaussian beams.A 64×1 phased array is performed in the numerical simulation.In the linear case,the difference between the results of the Gaussian superposition technique and the Fresnel integral is less than 0.5%,which verifies the feasibility of the approach.In the nonlinear case,the nonlinear fields of single-focus and double-focus modes are calculated.The results reveal that the nonlinear effects can improve the focusing performance,and the nonlinear effects are related with the source pressures and the excitation frequencies.