Chaotic property of cavitation nozzles

The mechanism of hydraulic cavitation is far from known for the complexity of itself. The core of the technology of hydraulic cavitation is 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 shapes,are collected by hydrophone experimentally. The state spaces of some selected signals are built on the base of Takens theorem, and their largest Lyapunov exponents are calculated. This experiment identifies and compares the chaotic properties of cavitation nozzle,and presents a new method for the design and the test of cavitation nozzles. Under this experimental condition, the results display that the largest Lyapunov exponent of these selected cavitation noise signals is 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 one of the three.