Design And Implementation Of A Hydrophone Sensitivity Real-time Test System Under High Hydrostatic Pressure

As one of the key technologies for deep sea scientific research and equipment development,deep sea acoustic technology will be vigorously developed,and deep water acoustic transducer technology is a very important technical support.Hydroacoustic transducers will have different electroacoustic performance under different hydrostatic pressures.A key factor that plagues the development of deep-water transducers is the "online" test of transducer performance.The atmospheric pressure pool can only measure the transducer at a depth of several meters.Performance indicators such as sensitivity,when the transducer is performing a high hydrostatic pressure test,it can only verify whether it is damaged under deep water pressure,but it cannot obtain its actual performance under deep water pressure.performance.The thesis focuses on a series of researches on the real-time testing of the sensitivity of the vector hydrophone under high hydrostatic pressure.This paper is based on the classic vector hydrophone open standing wave tube sound field calibration device.Firstly,in order to meet the pressure conditions,it is proposed to add a rigid closed cover structure at the end of the standing wave tube opening.Therefore,the theoretical and simulation methods are used to analyze the sound field distribution characteristics of the vector hydrophone sensitivity measurement environment under high hydrostatic pressure,that is,the hydroacoustic pressure-resistance acoustic tube model;At the same time,the modal analysis and harmonious response analysis of the pressure-resistant acoustic tube structure are performed.By analyzing the modal shapes and Frequency,the structural deformation of the sound tube at each characteristic frequency point is obtained,so as to optimize the sound tube structure;finally,based on elastoplastic mechanics as the theoretical basis,combined with simulation calculations,the pressure resistance of each component of the pressure sound tube is analyzed.Performance,guiding the structural optimization of the sound tube in terms of pressure resistance,ensuring its reliability and safety under pressure.Secondly,in order to reduce the difficulty of implementing the pressure-resistance test system for the vector hydrophone sensitivity under high hydrostatic pressure,the paper proposes to move the transmitter that was originally placed on the bottom end of the standing vertical wave tube to the outside of the sound tube,so that the entire pressure test In the implementation of the system,there is no need to consider solving the problem of high-pressure-resistant low-frequency transmitters.To this end,a set of vector hydrophone sensitivity measurement device with pressure-resistant performance was developed and built in the frequency range of 20-2000 Hz.The excitation method was placed,and the internal sound field distribution characteristics of the pressure-resistant sound tube were tested using standard hydrophone receivers,and compared with the simulation results.At the same time,in order to reduce the vibration interference caused by external excitation to the measurement,the paper analyzed the measurement data.FFT processing was performed;in the frequency range of 2-8k Hz,the built-in method of pressure-resistant transmitter was also studied;finally,in the pressure range of 0.5MPa-3MPa,a vector water that has undergone preliminary compression testing and sensitivity calibration is tested.The sensitivity of the listener was tested in real time,and the measurement results showed that the sound pressure channel and vector communication of the hydrophone under pressure changes No greater sensitivity change,variation is less than 2d B,within the uncertainties in the measurement system.