Transmitted Sound Field Calculation And Optimization Of Beampattern For Torpedo Conformal Array

Transmitted characteristic of acoustic array is an important performance for torpedo homing system. Compared to planar arrays, conformal arrays have complex baffle, intense mutual interaction between array elements and wide scan angle. These features greatly influence the transmitted characteristic of conformal arrays. Therefore, it has important theoretical and practical value to calculate the sound field of conformal arrays and improve its projecting properties. Currently, it is difficult for the analytical method to calculate the sound field of conformal arrays. So it needs to find a numerical method to solve this problem. In this paper, the model for calculating the sound field of conformal arrays using the boundary element method was presented. On this basis, the optimization of transmitted beampattern is investigated to make conformal arrays obtain a low-sidelobe transmitted beampattern and fine transmitted characteristic. The main contents are as follows:(1) An model to calculate the acoustic radiation of conformal arrays using the boundary element method is established. The sound field of planar array with 52 elements, spherical array with 36 elements, and cylindrical array with 36 elements were calculated. And the transmitted beampattern of elements and arrays, sound pressure distribution in near acoustic field were obtained. The research results show that the numerical method consider the acoustic effect of the baffle and the mutual interactions between array elements successfully, and can obtain an reasonable result.(2) The method to optimize the transmitted beampattern of conformal arrays is investigated. Both the boundary element model optimization method and the measured array manifold optimization method are proposed, which make the conformal array obtain a low-sidelobe transmitted beampattern and improve the directivity index. The optimized weighting vector was also calculated to make the conformal arrays obtain higher source level.(3) The non-optimization transmitted beampattern and optimization transmitted beampattern were measured in the anechoic water tank. And the experimental results verify that the model to calculate the sound field and the method to optimize the transmitted beampattern of the conformal arrays are valid and practical.