Comparative analysis of receiving characteristics of all flextensional transducer classes

Abstract

Flextensional transducers have been widely used as low-frequency projectors, and their characteristics can be exploited to develop hydrophones with better sensitivity and wider receiving bandwidth than other existing hydrophones in the low-frequency band. In this study, we compared and analyzed the receiving characteristics of different classes of flextensional transducers to identify the most suitable class for wideband low-frequency hydrophones, particularly for broad applications. To begin, we established an initial model with the same peak receiving-voltage-sensitivity (RVS) frequency for each class of flextensional transducers. Through a thorough analysis of various structural variables, we examined their impact on the receiving characteristics of the transducers. Based on these findings, we selected the design variables with the most significant influence on the bandwidth for each class. Subsequently, we determined the optimal combination of these variables to maximize the receiving bandwidth while maintaining RVS at or above 1 kHz. Comparing the performance of the best-fit models across all classes, we found that class IV flextensional transducers exhibit the widest low-frequency receiving bandwidth, closely followed by the convex class I. The −3 dB receiving bandwidth of the class IV transducer amounts to 87.6% of the peak RVS frequency, while the convex class I transducer achieves 67.1%.