声波测井单极换能器的近似理论分析

Theoretical Approximation of Monopole Transducers for Acoustic Logging Tools

提出一种声波测井单极换能器的近似理论模型,将换能器的振动近似等效为径向的一维振动,并根据声波波动理论与压电理论推导得到了换能器的理论响应解。在此基础上计算分析2种换能器结构的响应特性,计算结果与利用COMSOL软件的计算结果进行对比,两者基本一致,证实所提出的声波测井单极换能器近似理论模型的正确性。

As the most important part of an acoustic logging tool,the transducer should be specially designed so that it can shoot acoustic wave with strong power,less noises and appropriate frequency.This paper presents an approximate theoretical model which approximates the motion of the transducer to radial 1D vibration,and solves the theoretical response based on the acoustic wave theory and the piezoelectric theory,then analyzes the influences of materials and sizes on the signals shot by the transducer,and finally analyzes the response characteristics of two kinds of transducers.The approximate theoretical model improves calculation more significantly than a finite element model.And the results almost agree with those from COMSOL software,indicating the theoretical model of monopole transducers is effective.