STUDY OF THE ELECTROACOUSTIC CHARACTERISTICS OF THE COMPACT LOW-FREQUENCY HYDROACOUSTIC TRANSDUCER (3D LFHE) OF A LONGITUDINAL-BENDING TYPE AND A COMPLEX SHAPE

The results of studies of the resonant characteristics of a compact longitudinal-bending hydroacoustic transducer with an all-metal radiating shell of a complex shape — 3D LFHE —in air and an analysis of its electroacoustic characteristics in water are presented. An analysis of the distribution of the amplitude of vibrations over the device surface in air and electroacoustic parameters in water, obtained during full-scale tests, confirms that the radiator presented in the work with overall dimensions less than 120 mm and a weight of up to 1.2 kg is superior in a number of parameters to radiators of similar sizes, in particular, it has a higher values of the coefficient of mechanical transformation and the use of the added mass of water. Despite its compact size, the 3D LFHE presented in the paper has a voltage sensitivity of 1.6 Pa×m/V in water at a fundamental resonance frequency of 1.6 kHz, a relative bandwidth of at least 16%, and an efficiency in the operating frequency band of up to 90%. It is shown that after installing additional elements, the efficiency of 3D LFHE is increased due to reducing the level of vibrations of the end flanges outside the main frequency band. According to the calculations, the radiated acoustic power of such a 3D LFHE in the mode of transmission of binary phase-shift keyed signals can reach 50 W or more, which allows, taking into account the high reliability (confirmed service life of more than 1011 cycles) and manufacturability, to successfully use such hydroacoustic transducers for a wide range of problems in underwater hydroacoustics, navigation, and telecommunications.