FIV2018 Paper Management System, FIV2018 Conference

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Self-resonating frequency and cavitation noise of organ-pipe water jet
Yan Pan, Tengfei Cai, Fei Ma, Linbin Qiu, Lihua Cui

Last modified: 2018-04-20

Abstract


Flow-induced vibration and noise problems can lead to deleterious effects such as loss of performance and significant maintenance. While the strong oscillation and cavitation erosion of organ-pipe water jet can improve the working efficiency in fields like rock breaking and deep-hole drilling inversely. During the working process, there is great difference in the performance between resonating jet and off-resonating jet. The frequency property and cavitation behavior in different oscillating state is important for the jet technology. In this paper, the self-resonating oscillation mechanism of organ-pipe water jet is discussed and a reasonable structure of organ-pipe nozzle is designed. Based on the detection of the pressure pulse signal in pipeline outside the high-pressure tank and the acquisition of cavitation noise near the target plate inside the tank, the variation of frequency property and cavitation noise of organ-pipe water jet in different oscillation state is identified. The test results show that the jet frequency spectrum differs significantly in different oscillation state. The leading resonant nonlinear interaction between the characteristic frequencies is a triad resonance involving the sub-harmonic, the fundamental the 3/2 harmonic, which is also found in the shear layer by PETERSEN. The cavitation noise is characterized by its wide frequency spectrum, and the dominant jet-noise frequency is closely related to the vibration signal. The erosion capability of organ-pipe water jet is improved by its strong oscillation and cavitation effect. The study of organ-pipe water jet provide a theoretical base for the improvement of erosion effect of jet technology under submerged condition.

 


Keywords


nonlinear interaction

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