In the present study, the partial loss and distortion of turbine blades were acoustically detected while the turbine was rotating. An ultrasonic signal of a specific frequency (300 kHz) was transmitted in the form of continuous sine waves to the rotating turbine model. The signal was reflected on the turbine blade and received by a receiver. The amplitude of the given frequency component in the received signal was analyzed by signal processing. Because ultrasounds are attenuated easily when propagated into air and have a straight characteristic like light, the characteristics of the signals were examined by a quantitative test. The signal attenuation with respect to distance and the signal reduction by eccentricity were observed and compared with the experimental results. Partial loss decreased the sound reflection area; thus, the signal amplitude was reduced. The signal amplitude was inversely proportional to the size of the defect. Distortion caused larger eccentricity between the transmitter and the receiver. Weaker signals were detected with the more distorted blade. When the blade was distorted by more than 20dg, the amplitude of the signal decreased significantly. In short, defects of turbine blades cause a reduction in the acoustic signal. It was verified that acoustic diagnosis can be applied to detect the partial loss and distortion of turbine blades.

在本研究中，在涡轮旋转时通过声学方法检测了涡轮叶片的部分损失和变形。特定频率（300 kHz）的超声波信号以连续正弦波的形式传输到旋转涡轮模型。信号在涡轮叶片上反射并由接收器接收。通过信号处理来分析接收信号中给定频率分量的幅度。由于超声波在传播到空气中时很容易衰减，并且具有像光一样的笔直特性，因此通过定量测试检查了信号的特性。观察到相对于距离的信号衰减和由于偏心而导致的信号衰减，并将其与实验结果进行比较。部分损失减小了声反射面积。从而，信号幅度减小。信号幅度与缺陷的大小成反比。失真导致发射器和接收器之间更大的偏心率。用更扭曲的刀片检测到较弱的信号。当叶片变形超过20dg时，信号幅度会明显下降。简而言之，涡轮叶片的缺陷导致声信号的减小。证实了声学诊断可用于检测涡轮叶片的部分损失和变形。信号幅度显着下降。简而言之，涡轮叶片的缺陷导致声信号的减小。证实了声学诊断可用于检测涡轮叶片的部分损失和变形。信号幅度显着下降。简而言之，涡轮叶片的缺陷导致声信号的减小。证实了声学诊断可用于检测涡轮叶片的部分损失和变形。