水声材料声振特性的驻波管测量方法

A standing wave tube method for measuring acoustic and vibration characteristics of underwater acoustic materials

提出了一种基于驻波管的测量方法,以获得水声材料在静水压条件下的声学和振动特性参数。设计了带有气压补偿功能的低频发射换能器,作为驻波管的声源,通过水柱将换能器的平面活塞振动耦合到水面下的被测样品。在被测样品背衬上安装加速度计,测量样品背面振速;同时在管壁中嵌入一对水听器,测量水柱声压。导出样品声波入射面的振速和声压,进而计算出样品前表面和背衬面之间的振速传递系数(去耦系数)、样品的输入阻抗和声压反射系数。建立低频驻波管测试系统,声管尺寸为内径300 mm、外径600 mm、高3 m,工作频率范围100~1000 Hz,利用水层样品和多层穿孔橡胶样品开展了实验研究。实验结果显示,测量数据与仿真计算数据吻合较好,验证了测量方法的有效性。

A measurement method based on standing wave tube is proposed to get the acoustic and vibration characteristic parameters of underwater acoustic materials under hydrostatic pressure.A low-frequency emission transducer with pneumatic compensation is designed as the sound source for standing wave tube.Through a water column,the planar piston vibration of the transducer is coupled to the sample under the water surface.An accelerometer is installed on the backing of the tested sample to measure the vibration velocity of the sample backside.Meanwhile,a pair of hydrophones embedded in the tube wall is used to measure the sound pressure of the water column.Based on the measured data,the vibration velocity and sound pressure of the sample surface of incidence are derived.The vibration velocity transfer coefficient(decoupling coefficient)between the front and back surfaces of the sample,the input impedance,and the sound pressure reflection coefficient of the sample are then calculated.A lowfrequency standing wave tube test system is constructed with a tube size of 300 mm inner diameter,600 mm outer diameter,and 3 m in height,with a frequency range of 100 Hz to 1000 Hz.The experimental studies are conducted using water layer samples and multilayer perforated rubber samples.The results show good agreement with the simulation data,thus validating the effectiveness of the measurement method.