甚低频声源用新型电磁驱动结构的建模与分析

Modeling and Analysis of Innovative Electromagnetic Driving Structures for Very Low Frequency Sound Sources

摘要:

针对适装于无人反水雷平台的扫雷声源要求结构紧凑、输出位移大、甚低频辐射能力强的特点， 提出一种可模块化组装的新型电磁驱动结构。该驱动结构具有结构简单、输入–输出线性化、驱动力电流比高等优点。在分析该新型电磁驱动结构运行原理的基础上，建立了其等效磁路模型，进一步根据单自由度带阻尼受迫振动模型建立了新型电磁驱动结构的动力学模型。为验证等效磁路模型及动力学模型的正确性，建立了该驱动结构的有限元仿真模型，将仿真所得的电磁力及输出位移与基于等效磁路的仿真模型结果进行对比， 有限元分析结果和磁路分析结果较好吻合，证明了所建模型的准确性。进一步根据声辐射模型计算得到声源在 30~200 Hz 激励下的输出声源级，计算结果表明：所提出的新型电磁驱动结构驱动的甚低频声源在 70 Hz 谐振频率下，输出声源级可达 185 dB，在 30~200 Hz 频带内输出声源及均大于 145 dB，能够满足甚低频大功率输出的要求，且通过模块化组装能够实现高声源级输出，可为新型扫雷声源的设计提供理论支撑。

关键词:扫雷声源;甚低频;电磁驱动;电磁力

Abstract:

In response to the needs of unmanned mine countermeasures platforms，a novel electromagnetic driving structure is designed to achieve a compact structure，large displacement output，and powerful very low frequency（VLF） radiation capabilities. This structure is characterized by simple design，linearization of input and output，and a high driving force-to-current ratio. Based on the operating principles of the electromagnetic driving structure，an equivalent magnetic circuit model is established and the dynamic model is then established according to the single-degree-of-freedom damped forced vibration model. These models are verified through a finite element simulation model. The simulated electromagnetic force and output displacement are compared with the simulation results based on the equivalent magnetic circuit. The finite element analysis results are in good agreement with the magnetic circuit analysis results，which proves the accuracy of the models. Then，based on the sound radiation model，the output sound source level under 30~200 Hz excitation is calculated. The results show that the output level of the very-low frequency sound source driven by the proposed new electromagnetic driving structure can reach 185 dB at the resonant frequency of 70 Hz，and the output level of the sound source in the frequency band of 30~200 Hz is greater than 145 dB，which can meet the requirements of the very-low frequency high-power output，and the high sound source level output can be realized through modular assembly. It can provide theoretical support for the design of new minesweeping sound source.

Key words:minesweeping sound source;very low frequency;electromagnetic driving;electromagnetic force