空化喷嘴混沌特性的辨识

通过实验,使用高频水听器采集3种常用不同结构空化喷嘴产生的空化噪声信号,选取其中的信号,以Takens定理为基础,进行相空间重构,并分别计算其最大Lyapunov指数值。实验对空化喷嘴的混沌特性进行辨识以及比较分析,为空化喷嘴的设计、检测提供了一种新的途径。在采用的实验条件下,选取的空化噪声信号的最大Lyapunov指数值大于零,即这些信号都是混沌信号。实验显示,具有自激振荡腔结构喷嘴的最大Lyapunov指数值最大。

Identification of the Chaotic Property of Cavitation Nozzles

The mechanism of hydraulic cavitation is far from known for the complexity of itself.The core of the technol-ogy of hydraulic cavitation is the cavitation nozzle.Researches show that cavitation phenomenon displays some chaotic properties.On this basis,the cavitation noise signals,which are produced by the common cavitation nozzles in different shapea,re collected by hydrophone experimentally.The state spaces of some selected signals are built on the base of taken theorema,nd their largest Lyapunov exponents are calculated.This experiment identifies and compares the chaotic properties of cavitation nozzle,and presented a new method for the design and the test of cavitation nozzles.Under this experimental conditiont,he result displays that the largest Lyapunov exponents of these selected cavitation noise signals are larger than 0,which means that these signals are all chaotic signals.The largest Lyapunov exponent of the nozzle with self-oscillating cavity is the largest of the three.