铁镓单晶Janus-Helmholtz换能器

针对深水、低频、宽带换能器的技术需求,结合Janus-Helmholtz换能器的结构特点和铁镓单晶材料低场应变大及机械强度高的特性,提出了铁镓单晶Janus-Helmholtz换能器设计方案。采用永磁偏磁场和环形闭合磁路,建立了一系列铁镓单晶磁致伸缩换能器理论分析模型,包括对磁致伸缩材料参数进行线性化处理,设计了换能器最佳工作点,结合静态磁场和动态磁场分布情况分段细化换能器驱动等效参数,以及利用全阻抗模型通过电感损耗等效计算换能器静态阻抗,然后通过二维有限元分析等效模型,优化分析了换能器的结构参数与电声性能。最后制作了换能器样机,并进行了测试与分析。对比仿真和测试结果表明:全阻抗模型得到的阻抗曲线与样机测试结果相一致,有限元等效模型计算的发送电流响应与样机测试结果良好吻合。换能器样机水中谐振基频为1000Hz,谐振频率下发送电流响应176.4dB;在875~2300Hz频率范围内,发送电流响应起伏不大于6dB;增加驱动电流有效值到16.2A,最大声源级可以达到196.2dB。

Fe-Ga single crystal Janus-Helmholtz transducer

The design of Janus-Helmholtz transducer driven by the iron-gallium (Fe-Ga) single crystal material is proposed. Because both the large low-field strain and high mechanical strength characteristics of Fe-Ga single crystal material and the structural advantages of Janus-Helmholtz transducer could be used effectively, it has the potential to meet the fast growing requirement of deep-water, low-frequency and broadband transducer. A series of theoretical analysis models for a Fe-Ga single crystal transducer with permanent magnetic bias magnetic field and annular closed magnetic circuit are established at first, including the linearization processing method of the magnetostrictive material parameters, the segmented magnetic circuit technique to refine the equivalent driving parameters according to the distribution of static and dynamic magnetic field, and the full impedance model to calculation of static impedance of transducer through the inductance loss. Then the optimization on the structural parameters and the electro-acoustic performance is done by the two-dimensional equivalent finite element analysis model. At last a prototype is made and measured. It is confirmed that the experimental results of the impedance and the transmitting current response are in good agreement with the predictions of the full impedance model and the equivalent finite element model respectively. The fundamental resonance frequency is 1000Hz with the transmitting current response of 176.4dB. The fluctuation of the transmitting current response is no more than 6dB in the frequency range from 875Hz to 2300Hz. And the maximum source level could reach 196.2dB when the driving current is 16.2A.