| 超声波在水中衰减的频率效应及其对脉冲回波的影响 |
| Frequency Effect of Ultrasonic Wave Attenuation in Water and Its Influence on Pulse Echo |
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| 中文摘要: |
| 超声波在传播中会发生幅值衰减，该衰减不仅与超声波传播的距离有关，还与超声波的频率有关。为了研究高频超声波衰减的频率效应，本文通过脉冲回波法分析脉冲超声波在水中传播反射回波的幅值和频谱变化，研究了超声波在水中传播时幅值衰减与传播距离及其与超声频率之间的关系，通过测量脉冲超声波在水中传播不同距离时的反射回波，并对其进行傅里叶变换，分析了超声波传播衰减的距离效应和频率效应。研究发现：超声波在水中的传播衰减随距离呈指数规律，且不同频率超声波的衰减系数不相同，频率越高，衰减越大，衰减的频率效应可有效解释反射法高频脉冲超声检测中回波脉冲信号的中心频率远低于换能器标称中心频率的现象。 |
| 英文摘要: |
| The amplitude of ultrasonic wave is attenuated in propagation, and the attenuation is related to the distance of propagation and the center frequency of ultrasonic transducer. In order to study the frequency effect of high-frequency ultrasonic attenuation, this paper analyzes the amplitude and spectral variation of pulsed ultrasonic wave reflection in water by pulse echo method, and studies the relationships between the amplitude attenuation and the propagation distance of ultrasonic wave in water as well as its ultrasonic frequency. The reflected echoes at different distances are collected, and the echoes are subjected to Fourier transform to analyze the distance effect and frequency effect of ultrasonic propagation attenuation. It is found that the propagation attenuation of ultrasonic waves in water is exponential with distance, and the attenuation coefficients of ultrasonic waves of different frequencies are different. The higher the frequency, the greater the attenuation. The frequency effect of attenuation can effectively explain that the center frequency of the echo pulse signal is much lower than the nominal center frequency of the transducer in high-frequency pulse ultrasonic detection by reflection method. |
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| 中文关键词: 高频脉冲超声 传播衰减 衰减系数频谱 |
| 英文关键词:high frequency pulse ultrasonic propagation attenuation attenuation coefficient spectrum |
| 基金项目: |
| DOI：10.11823/j.issn.1674-5795.2020.01.04 |
| 引用本文：程明，潘勤学，肖定国，徐春广，刘然，杨超.超声波在水中衰减的频率效应及其对脉冲回波的影响[J].计测技术,2020,(1):. |
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