Characteristic Simulation And Test Analysis Of Ultrasonic Transducer For Flow Measurement

Ultrasonic flowmeter is a widely used flowmeter tool in the field of flowmeter measurement.It has the characteristics of convenient installation,maintenance,versatility and high precision.The ultrasonic flowmeter involved in this subject is an ultrasonic flowmeter based on the time difference method,and the ultrasonic transducer is an important component thereof.Whether the comprehensive performance index of the transducer matches the measurement accuracy of the flowmeter.At present,although there are many researches on ultrasonic transducer testing methods and performance improvement,the research on paired transducer index matching is still lacking.To solve this problem,this topic uses COMSOL software to establish dual ultrasonic transducers.The energy conversion model and the ultrasonic transducer test model are designed to complete the simulation measurement of the ultrasonic transducer comprehensive index and complete its characteristic analysis.The main research contents of this thesis are as follows:Firstly,the structure of the ultrasonic transducer and the principle of piezoelectric effect are analyzed.The theoretical equivalent circuit of the ultrasonic transducer is derived and the expressions of various comprehensive performance indexes are obtained.According to the expression,the comprehensive performance index changes with temperature.Trends and effects on the conversion efficiency of ultrasonic transducers.Secondly,using the COMSOL simulation software,the energy conversion model of the dual ultrasonic transducer and the comprehensive performance index test model of the ultrasonic transducer were established.Through the energy conversion model,the surface amplitude of the receiving transducer and the complete oscillating,balancing and vibration absorbing waveforms can be obtained.The modal analysis of the ultrasonic transducer is completed by the comprehensive performance index test model,that is,the ultrasonic transducer is analyzed.The vibration state of different modes is selected and the vibration mode of the thickness direction is selected,and the frequency parameters,impedance parameters,static capacitance and receiving amplitude of the ultrasonic transducer are further measured.Finally,the test results of the model are verified and the model is used for characterization.The model is calibrated according to the laboratory's existing ultrasonic transducer test equipment.Using the model to test the existing transducers in the laboratory and record the values of various parameters at different temperatures to analyze its variation with temperature;change the thickness parameters of piezoelectric ceramics and analyze its influence on the performance index of ultrasonic transducers;analysis The impact of performance indicator matching on conversion efficiency.