大面积高分子压电薄膜水听器对湍流边界层压力起伏的自噪声响应

The self-noise response of a large-planar PVDF hydrophone to turbulent boundary layer pressure fluctuation

分析大面积高分子压电薄膜水听器（PVDF）水听器在湍流边界层压力起伏（TBLPF）作用下的电压响应。推导了利用TBLPF的波数频率谱密度和水听器的响应函数来计算TBLPF激励下水听器输出电压的自功率谱密度的一般表达式，并利用转移矩阵法求解了水听器理论模型的响应函数。还计算了该水听器的灵敏度和其对TBLPF响应的等效平面波声压谱密度级。结果表明，大面积PVDF水听器的灵敏度和其对TBLPF的响应谱可能出现弯曲振动谐振峰，这些峰仅靠增加表面覆盖层的厚度是难以抑制的。讨论了避免或抑制这些峰的可能方法。

In this paper, the self-noise response of a large-planar PVDF hydrophone to turbulentboundary layer pressure fluctuation (TBLPF) is investigated. The general expression is deduced, inwhich TBLPF wave-number frequency spectrum and the response function of hydrophone are used tocalculate the auto-spectrum of output voltage of hydrophone excited with TBLPF. The response functionof hydrophone is calculated by transfer matrix method. The sensitivity of hydrophone and the powerspectrum density for equivalent plane wave pressure of its response to TBLPF are also calculated. Itis shown that both the sensitivity of hydrophone and its response to TBLPF have some peaks. Thesepeaks are due to fie-cural vibration of hydrophone and they are difficult to be reduced by increasing thethickness of the coating. Some methods to avoid or reduce these peaks are discussed.