空化流动诱导离心泵低频振动的实验研究

空化流动严重影响泵安全稳定运行,为充分认识泵内空化发展程度及其诱导的低频振动特性,设计了一台离心式模型泵作为研究对象,同时采用高速摄影及振动加速度测试手段,实现了叶轮内部空化流动的可视化及对应的泵体低频振动信号提取,分析了空化泡形态随空化发展的演化规律,对比了空化发生前后泵体低频振动频谱特性,探讨了泵体总振级水平、离散频率下振动加速度幅值随空化发展程度的变化,提出振动临界汽蚀余量可作为空化程度的另一判据,叶频时的振动加速度幅值变化亦可作为泵内空化程度的表征。

Experimental Study on Cavitation Induced Low Frequency Vibration in a Centrifugal Pump

Pump cavitation affects the safe and stable operation.A centrifugal model pump was designed for experimental study on the pump cavitation induced low frequency vibration.High-speed camera was utilized in the test for cavitation flow visualization.Vibration accelerators were adopted to capture the pump low frequency vibration signals.The evaluation process of cavitation bubbles was analyzed as cavitation developing.Meanwhile,comparison was carried out between low frequency spectra features before cavitation and that in fully developed period.Total vibration levels, accelerations at discrete frequency were discussed as well at different cavitation stages.It is proposed that vibration critical value can be used as a criterion of cavitation levels.Vibration acceleration amplitudes at blade pass frequency also may be used to indicate the cavitation development in pumps.