衍射现象对活塞式声源超声场分布的影响
The effect of diffraction on ultrasonic sound field of plane piston source
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摘要: 超声波由于其良好的指向性,可被广泛应用于海洋探测与开发、无损检测与评估、医学诊断等应用领域。基于KZK方程,利用频域有限差分方法对衍射现象进行分析,计算了活塞式声源的基波和高次谐波声场,发现高次谐波和基波具有类似的声场分布特性,并且谐波阶次越高,径向扩散越少,声场特性越好。研究获得了超声波在空气中传播的声场特性,分析了基波及各次谐波的指向性优劣以及传播范围的大小。在研究的过程中,利用MATLAB等数学工具,对研究结果进行了数值计算和模拟。以上结果为研究超声波的声场特性提供了一定的参考,对研究超声波声场的指向性有着实际性的意义。Abstract: Based on the KZK equation in frequency domain,the finite difference method is used to analyze the phenomenon of diffraction and calculate the fundamental and higher harmonic sound field of a plane piston source.The research finds that the sound fields of high-order harmonic and fundamental have similar characteristics,and higher order harmonic has less radial diffusion and better sound field.The ultrasonic field characteristic in the air is studied.The di-rectivities and propagation distances of the fundamental and harmonics are analyzed.MATLAB and other mathematical tools have been used for the analysis of the numerical results and simulation.The results provide a reference for the study of the characteristics of ultrasonic sound field.