回波主动抑制的次级水声发射单元设计与优化

Traditional coating layer for underwater vehicles mainly depend on material renewal and structure optimization, which is difficult to cope with low-frequency active sonar detection. A lightweight, thin and low-frequency broadband underwater acoustic emission unit with high pressure resistance is designed based on the giant magnetostrictive material. The design and optimization process of the core components are analyzed emphatically, and the finite element simulation results are verified by the PSV-400 laser vibriometer. The optimal boundary constraints of the active emitting element are determined through the modal analysis of a fixed radiation panel. Compared with the performance of the emission unit in the original configuration, it is found that, under the premise of maintaining good directivity of underwater acoustic emission, the highest resonance frequency below 2 000 Hz is reduced by more than 10% based on the finite element analysis. Based on the acoustic structure coupling analysis, the maximum radiation source level of active emission unit in the low frequency range is 147. 48 dB, which is increased by 4. 65% . The frequency bandwidth of transmitting unit exceeds 1 500 Hz when the sound source level is higher than 100 dB. This means that there is a higher sound power level in this frequency bandwidth range. The emission unit can provide technical support for the application of array in the large-scale acoustic cladding. It has certain academic research value and broad engineering application prospect.