水下永磁推进电机声振特性分析及抑制

Analysis and suppression of acoustic vibration characteristics of underwater permanent magnet propulsion motor

噪声在水下传播速度更快,幅值更大,随着水下声学探测技术的快速进步,水下推进场合对推进电机运行时振动噪声性能要求更高。本文首先通过对电机的电磁力波和定子结构模态的计算,分析推进电机在定子铁心的共振特性。然后有限元谐响应联合仿真分析定子表面振动和噪声辐射特性,发现水下噪声的幅值主要由于电机0阶和2阶力波产生,因而在设计抑制噪声的机壳时,重点抑制0阶和2阶共振的噪声幅值。最后设计了较优径向厚度15mm的电机机壳,声压级降低了29dB。经实际样机在消声水池测试,辐射噪声最大声压级为125dB,在100~5000Hz频带内测试结果最大声压级115dB左右,与分析结果基本吻合,为水下推进电机振动噪声的分析和抑制提供了参考。

With the rapid progress of underwater acoustic detection technology,the vibration and noise performance of underwater propulsion motor is required to be higher.Firstly,through the calculation of the electromagnetic force wave and the stator structure mode of the motor,the resonance characteristics of the propulsion motor in the stator core are analyzed.Then the finite element harmonic response joint simulation analyzes the stator surface vibration and noise radiation charac-teristics.It is found that the amplitude of underwater noise is mainly caused by the O-order force wave and the 2-order reson-ance of the motor.Therefore,when designing the enclosure to suppress noise,the noise amplitude of the O-order and 2-order resonance should be suppressed.At last,the motor casing with a better radial thickness of 15 mm is designed,and the sound pressure level is reduced by 29 dB.After the actual prototype is tested in the silencing tank,the maximum sound pressure level of radiated noise is 125 dB,and the maximum sound pressure level is about 115 dB in the frequency band of 100~5000 hz,which is basically consistent with the analysis results,providing a reference for the analysis process and sup-pression emphasis of underwater propulsion motor vibration and noise.