Research of Vector Sensor of Towed Array
|School||Harbin Engineering University|
|Keywords||towed array vector hydrophone MEMS suspension model|
Combined vector hydrophones possess acoustic pressure channels and vector channels,which have the same equivalent acoustic center and can synchronously and co-locationallymeasure underwater scalar and vector acoustic signals to completely describe the informationof sound field. Recently, co-oscillation vector hydrophone has been the most commonly usedtype in engineering application for its simple measurement principle, high sensitivity anddirectivity and convenient employment.In this thesis, the vector sensor having low frequency, high sensitivity and small sizedimension and presenting irregular cylinder with two half ball caps on each end is studiedhere to meet the requirements of the line towed array, based on the actual demand inunderwater acoustic engineering. Some works about the design, built and calibration of vectorhydrophone along with researches on the application in towed array is also did here. Finiteelement software named COMSOL Multiphysics is utilized in this paper, to compute andcompare the directivities and velocity ratios of different acoustic receivers based on threestructures of sphere, cylinder and capsule. Then two flexible receiver suspensions modelaccording to acoustic sphere and cylinder receivers are analyzed and an approximatesuspension model of capsule body is proposed subsequently. Finally, ten two dimensionalcombined vector hydrophones are design and built.The combined vector hydrophones designed and manufactured in this paper, have thesame dimension of Φ20×35mm, with the working frequency band of10~2000Hz, an averagedensity of1150kg/m3. The actually measured sensitivities of sound pressure channels is-202~-198dB (0dB ref1V/μPa), as well as the sensitivities of vector channels,-190dB~-188dB (1000Hz,0dB ref1V/μPa). These vector sensors’ directivity patterns tallywith cosine well in the working frequency band, satisfying the application requirements oftowed array.