Abstract: Aiming at increasing design efficiency of the jet nozzle and improving scouring and cleaning efficiency of water jet, based on theoretical analysis of the mechanism of self-resonating cavitating (SRC) jet nozzle, different units of organ-pipe SRC jet nozzles are designed. The vibration of organ-pipe SRC jet nozzle and target is measured during the jet process. The vibration characteristic and frequency characteristic of SRC water jet are studied by the comparative analysis of the vibration signals. It is found that the high frequencies in the vibration frequency-domain map of SRC jet nozzles are caused by the high frequency vibration due to the impact of broken bubbles in the resonator, the modulation frequency, i.e. harmonic frequency of self-resonating in the resonator of SRC jet nozzles is found in the vibration frequency-domain map of SRC jet nozzles. The measured value is consistent with that of the theoretical calculation. The effects of the main structural parameters, i.e. nozzle diameter, resonator length of an organ-pipe SRC jet nozzle on SRC water jet are obtained, and the optimum structural parameters of SRC jet nozzle are obtained according to setting testing system. The result of vibration analysis experimental research is in good agreement with that of simulation study, and the effective method of optimum design of SCR jet nozzles is obtained.

Key words: Jet nozzle, Optimum design, Vibration analysis, Vibration characteristic