水听器一致性对材料声反射系数全息反演精度的影响

Effect of hydrophone consistency on material sound reflection coefficient holography reconstruction precision

采用近场声全息(NAH)法进行材料声反射系数测试时,一般采用水听器阵列进行全息数据采集。针对阵元通道之间的幅度和相位一致性对全息反演结果的影响,在不同扫描方式下进行了仿真分析。根据仿真结果,建议采用水听器阵单面隔行的扫描方式进行测量。利用耦合腔校准方法对水听器阵进行通道间幅值和相位不一致性校准,并在消声水池中进行了矩形钢板的声反射系数全息测试实验。数据处理结果表明:采用经耦合腔校准后的水听器阵进行材料声反射系数测试,全息反演精度有所提高。

The hydrophone array is generally used for holography data acquisition when material sound reflection coefficient is measured by near-field acoustic holography （NAH） method. Aiming at effects of amplitude between channels of array unit and phase consistency on holography reconstruction results, simulation analysis is carried out in different scanning conditions. According to the simulation results, it is recommended that the measurement should be interlaced scanning in the same holography plane by the hydrophone array. The amplitude and phase inconsistencies of the hydropbone channels are calibrated by the couple cavity method, and then the sound reflection coefficient of a rectangular plate is measured in the anechoic tank. The data processing results show that the hydrophonc reconstruction precision is improved after the holography array is calibrated by the couple cavity method.