离心泵入口压力在汽蚀工况下的分频带混沌特性研究  

Chaotic characteristics of multi-frequency band of centrifugal pump inlet pressure under cavitation condition

作　　者：梁超[1] 周云龙[1] 杨宁[1] 刘起超 UANG Chao;ZHOU Yunlong;YANG Ning;UU Qichao(School of Energy and Power Engineering,Northeast Electric Power University,Jilin 132012,China)

机构地区：[1]东北电力大学能源与动力工程学院,吉林吉林132012

出　　处：《振动与冲击》2020年第23期71-77,共7页Journal of Vibration and Shock

基　　金：吉林省科技厅计划发展项目(20130206008GX)。

摘　　要：使用动态压力传感器采集了离心泵在不同有效汽蚀余量(NPSHa)下的入口压力脉动信号。对压力信号进行3层8频带的小波包分解。将小波包分解系数作为时间序列并计算出3个混沌特征参数:最大李雅普诺夫指数、关联维数、K2熵;分析并讨论了这些参数的特点和变化规律。结果表明,8个频带中的分解系数,前3个频带数据全都具有典型的混沌特征,3个混沌特征参数从不同角度描述系统的混沌特性,能够把不同NPSHa值所对应的汽蚀工况划分成4个不同的汽蚀阶段。Pressure fluctuation signals of a centrifugal pump inlet under different effective net positive suction head available(NPSHa) conditions were measured using dynamic pressure sensors.The3-layer 8-band wavelet packetdecomposition was done for the pressure signals.Wavelet packet decomposition coefficients were taken as time series to calculate 3 chaotic characteristic parameters including the maximal Lyapunov exponent, correlation dimension and K2 entropy. These parameters’ features and changelaws were analyzed and discussed. Results showed that the first 3 of decomposition coefficients in 8-band all have typical chaotic features;3 chaotic characteristic parameters can be used to describe the system’s chaotic characteristics from different angles, and divide cavitation conditions corresponding to different NPSHa values into 4 different cavitation stages.

关 键 词：离心泵 汽蚀 小波包 频带 混沌特性 

分 类 号：TH311[机械工程—机械制造及自动化]