research and development of underwater acoustic transducer
Publish Time: 2019-02-18 Origin: Site
Transducer characteristics and calibration methods
A hydroacoustic transducer is a device that converts acoustic energy and electrical energy each other. The position in sonar is similar to the antenna in a radio, an acoustic system that emits and receives sound waves in seawater. A piezoelectric transducer ultrasound in which acoustic energy is converted into electrical energy is called a receiver or a hydrophone; a transducer that converts electrical energy into acoustic energy is called a transmitter. Some sonars use the same transducer to transmit and receive sound; others use separate emitters and hydrophones.
Transducer characteristics
Hydrophone performance mainly refers to sensitivity and directionality. The receiving response of the hydrophone is the receiving sensitivity.
In order to ensure the performance of the underwater acoustic equipment and the need for the transmission of the values, the hydrophone and transmitter must be calibrated. Calibrating a acoustic piezoelectric tubes is a function of the frequency and directivity of the transducer response. There are now a large number of methods for measuring transducer response. a summary of the calibration methods compiled by the Naval Ordnance Laboratory T.F. Johnston based on the literature. These methods have their own advantages and disadvantages for different transducer sizes and frequency ranges.
PZT piezoelectric ceramics are developing towards industrialization. So far, lead zirconate titanate (PZT) piezoelectric ceramics have been used as water.The transducer material of the acoustic transducer still dominates. PZT piezoelectric ceramics developed by China Institute of Acoustics, commonly used models are PZT-4 (transceiver and dual-use), PZT-5 (receiving type) and PZT-8 (high-power emission type), and their performance can meet various underwater sounds. The needs of the transducer are compared to those of foreign countries. Transducing materials and acoustic materials Piezoelectric ceramics are developing towards industrialization.So far, lead zirconate titanate (PZT) piezoelectric ceramics still ranks first as the energy-transducing material for underwater acoustic transducers. PZT piezoelectric ceramics developed by China Institute of Acoustics, commonly used models are PZT-4 (transceiver and dual-use), PZT-5 (receiving type) and PZT-8 (high-power emission type), and their performance can meet various underwater sounds. They are needs of the transducer, its level and the foreign phase piezoelectric tube transducer d33 is measuring instrument developed in the piezoelectric ceramic measurement,which has been promoted more than 100 domestic,and edited the standard National Standard for Static Piezoelectric Strain Constant Measurement Method.Hydroacoustic materials mainly include sound absorption, anti-sound, sound and sound insulation materials, vibration damping materials and other research content. In this respect, the company has established the first underwater acoustic pulse tube test equipment, Fuyang's modulus and complex shear modulus test equipment, and is equipped with variable temperature and pressure device and microcomputer data processing system and high acoustic characteristics measurement system. In the field of sound absorbing materials, two kinds of water have been developed.They are acoustic sound absorbing material and three kinds of sound absorbing structure: flat cusp parallel channel type, square cusp and flat resonance type, which can meet the requirements of different frequency bands. The flat sound absorption tip has been widely used in the large and medium-sized muffler pools in China, and the sound pressure reflection coefficient is less than 10% in the frequency range of 8 to 100 kHz. In addition, T801 ~ T808 type sound-permeable rubber, cast type room temperature vulcanization, high-frequency sound absorption and sound-permeable materials, high sound absorption lining, sound absorption damping and putty type damping materials have been widely used in various engineering projects.Ultrasound simulation module series and ultrasonic simulation module series developed by ultrasonic human body tissue is the medical ultrasonic diagnostic instrument detection standard confirmed by the State Bureau of Technical Supervision and the State Administration of Medicine.
The most commonly underwater acoustic transducers are flat piston type, longitudinal vibrator horn type, round calibration type and curved type. China can design and manufacture various transducers that meet the needs of engineering, and the level is comparable to that of foreign countries.
(1) High-power transmitting transducer
The high-density emission transducer (inlaid cylindrical transducer) of the ring is obtained, and the scientific and technological achievements of the Chinese Academy of Sciences are obtained. Among them, the "piezoelectric ring electrode" has obtained the utility model patent. The transducer is the first deep sea broadband in China. The high-power underwater acoustic emission transducer is used for sea-water exploration of the sea area. The technology has been successfully applied in acoustic systems such as underwater acoustic receivers, underwater positioning speedometers and analog targets.
(2) bending transducer
The vibration and sound radiation of the lantern-type flexural transducer were studied and analyzed by the finite element method, and the results have been widely applied to sonar equipment. Based on this, a concave bending transducer was also studied. Compared with the existing convex lantern-type bending transducers in the world, this transducer has higher sensitivity and volumetric speed, and is resistant to static pressure. In particular, this structure can achieve high broadband by using multimode vibration. The characteristics are highly praised by foreign water acoustic.
(3) Research on piezoelectric composite hydrophone and rock transducer using PZT (3-3) sandwich composite piezoelectric material, the piezoelectric constant gh value is high and the figure of merit dh × gh is large and the vibration mode is better. Simple, and easy to match the characteristics of rock mass developed into broadband high sensitivity hydrophone and broadband narrow pulse rock ultrasonic transducer.
Process of Transducer: