Mechanical Engineering Faculty, Amirkabir University of Technology, 424, Hafez Avenue, Tehran, Iran.
Ultrasonics. 2014 Jan;54(1):168-76. doi: 10.1016/j.ultras.2013.04.008. Epub 2013 Apr 19.
The acoustic impedances of matching layers, their internal loss and vibration amplitude are the most important and influential parameters in the performance of high power airborne ultrasonic transducers. In this paper, the optimum acoustic impedances of the transducer matching layers were determined by using a genetic algorithm, the powerful tool for optimizating domain. The analytical results showed that the vibration amplitude increases significantly for low acoustic impedance matching layers. This enhancement is maximum and approximately 200 times higher for the last matching layer where it has the same interface with the air than the vibration amplitude of the source, lead zirconate titanate-pizo electric while transferring the 1 kW is desirable. This large amplitude increases both mechanical failure and temperature of the matching layers due to the internal loss of the matching layers. It has analytically shown that the temperature in last matching layer with having the maximum vibration amplitude is high enough to melt or burn the matching layers. To verify suggested approach, the effect of the amplitude of vibration on the induced temperature has been investigated experimentally. The experimental results displayed good agreement with the theoretical predictions.
匹配层的声阻抗、内部损耗和振动幅度是高功率机载超声换能器性能中最重要和最有影响力的参数。在本文中，我们使用遗传算法确定了换能器匹配层的最佳声阻抗，遗传算法是优化领域的有力工具。分析结果表明，低声阻抗匹配层的振动幅度显著增加。在最后一层匹配层中，这种增强最大，大约是 200 倍，因为它与空气的界面与源的振动幅度相同，在传输 1kW 时是理想的。这种大的振幅增加了匹配层的机械故障和温度，因为匹配层的内部损耗。分析表明，具有最大振动幅度的最后一层匹配层的温度足够高，足以使匹配层熔化或燃烧。为了验证所提出的方法，实验研究了振动幅度对感应温度的影响。实验结果与理论预测吻合较好。
