轴流转桨式水轮机空化声信号特征研究

Research on the Cavitation Acoustic Signals Charactoristic of Kaplan Turbine

影响水轮机使用寿命与性能的一个主要问题是空化空蚀现象,通过声信号检测空化是空化空蚀研究的重要领域,其中主要的难题是确定不同空化程度时声信号的特征。在轴流转桨式水轮机模型空化试验中,用宽频传感器测试不同空化程度下的声信号,分析声信号的频谱特征随空化发展的变化规律,结果表明,随着空化的发展,声信号频谱变化明显,且各个不同频段的变化率不同,揭示了通过声信号各频段的相对幅度来确定空化发展的严重程度的可能性。

Cavitation and erosion are severe problems, which may shorten the life of hydro-turbine. Measure the cavitation by monitoring the acoustic signal of the hydraulic turbine is one of the most important field in cavitation and erosion research. The key problem is to know the characteristic of acoustic signal with the cavitation. Width-frequency acoustic signal obtained from the model cavitation test is analyzed. The spectrum analysis result show that the change of the general acoustic signal characteristic is manifest with the cavitation development, and that the change of the vary frequency is different. The way of monitoring cavitation is very possible through discriminating the vary frequency relative amplitude of acoustic signal.