压力罐中水声材料声学特性的参量源测量法

设计了一种原波频率500 kHz、差频范围1~30 kHz的截断宽带参量阵,作为水声材料测量系统的声源。通过分析典型频率下的宽带参量源指向性理论计算和实际测量结果,发现两者结果的曲线基本吻合,证明计算模型是正确的。应用钟形短时脉冲实现水声材料声特性的宽带测量,有益于降低样品边缘衍射干扰。并建立了测量水声材料大面积板状样品声压反射系数、声压透射系数和吸声系数的压力罐测量系统,罐体内尺寸Φ4 m×12 m,最高静水压4.5 MPa,测量频率范围1~30 kHz。对标准样品(尺寸1m×1m)进行了测量实验,其测量结果和理论曲线有很好的吻合,参量源测量法得到了验证;之后,通过对一块橡胶板样品在不同静压力下的吸声性能进行了测量和有效评估,进一步确认了参量源测量法在压力罐这样有限水域中的潜在应用价值。 

The parametric source measuring method for characteristics of underwater acoustic materials in a pressure vessel

A kind of truncated wideband parameter array with a primary frequency of 500 kHz and a difference frequency range of 1 kHz to 30 kHz was designed as a sound source of acoustic materials measurement system.By analyzing the theoretical calculation and actual measurement results of the array directivity of the truncated wideband parameter source in typical frequencies,it was showed that their result curves were basically consistent,and the model was correct.The application of bell-type short-duration pulse could carry out wideband measurements for characteristics of underwater acoustic materials,and reduce the effects of diffraction from the panel edges.The measurement system was established in Hangzhou Applied Acoustic Research Institute for measuring the sound pressure reflection coefficient,pressure transmission coefficient and absorption coefficient of the large area panel sample of underwater acoustic material in the pressure vessel.The size of tank is Φ 4 m×12 m,the maximum hydrostatic pressure is 4.5 MPa,and the measuring frequency range is 1-30 kHz.The measurements for standard sample (the size of 1 m×1 m) showed that the measured curves had a good agreement with theoretical curves,the measurement method was verified.Then,the sound absorption property of the rubber plate sample was measured and effective assessed under different hydrostatic pressures.The potential application value of parameter source using in the limited water area such as pressured vessel is confirmed further.