聚焦换能器声强和声功率测量方法研究

发布时间：2019-03-16 18:05

【摘要】：针对聚焦声场的特点,以及辐射力天平(RFB)只能获得单一功率指标的缺点,提出一种基于近场测量法的聚焦换能器声强和声功率评价方法。通过声场测量系统对聚焦换能器预聚焦区域中两个平面上的声压扫描测量,运用声强法得到聚焦换能器的声强分布以及辐射声功率。采用活塞换能器的远场测量法与近场测量法进行比对,两种方法得到的声功率误差不超过12%。比较预聚焦区域声功率值和焦点处声功率值,分析声功率评价方法的准确性。发现聚焦声场中不同位置处的声功率值一致性误差5%,同一位置处的声功率值重复性误差2%。结果表明,近场测量法适用于对聚焦换能器声强和声功率的评价,可有效避免直接测量对测量设备的损坏,同时还克服双水听器声强互谱法频率上限低以及测量系统相位不匹配的缺点。
[Abstract]:In view of the characteristics of the focused sound field and the disadvantage that the radiation force balance (RFB) can only obtain a single power index, a method for evaluating the sound intensity and sound power of the focused transducer based on the near-field measurement method is proposed. The sound intensity distribution and the radiation sound power of the focused transducer are obtained by using the sound intensity method to measure the sound pressure on two planes in the pre-focusing region of the focused transducer by the sound field measurement system. Comparing the far-field measurement method of piston transducer with the near-field measurement method, the error of sound power obtained by the two methods is less than 12%. The accuracy of the sound power evaluation method is analyzed by comparing the acoustic power values in the prefocus region with the acoustic power values at the focus. It is found that the consistency error of sound power value at different positions in the focused sound field is 5%, and the repeatability error of sound power value at the same position is 2%. The results show that the near-field measurement method is suitable for evaluating the sound intensity and sound power of the focusing transducer, and can effectively avoid the damage to the measuring equipment caused by direct measurement. At the same time, it also overcomes the disadvantages of low upper frequency limit and phase mismatch of the measurement system in the double hydrophone acoustic intensity interspectral method.
【作者单位】：中国计量大学计量测试工程学院;
【基金】：国家自然科学基金项目(11474259)
【分类号】：TB52

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