Nozzle resonance mechanism and cooperative optimization of self-excited oscillating pulse cavitation jet

Abstract

The peak value and pulsation amplitude of the self-excited oscillating pulse cavitation jet nozzle are essential indices to evaluate the jet performance. We established a simulation model of the jet process of the nozzle to investigate the evolution mechanism of the inner and outer flow fields. We used the chamber fillet, chamber diameter, chamber length, and outlet-tube diameter as the design variables, and the peak value of the striking force and the amplitude of the pulsation of the striking force as the target variables. The collaborative optimization design method of the nozzle was determined by combining the orthogonal test method, the back propagation neural network, and the nondominated sorting genetic algorithm. As indicated by the results, when the inlet pressure was 3 MPa, the factors ranked as follows in terms of their effects on the jet performance of the nozzle: the chamber fillet, the outlet-tube diameter, chamber diameter, and the chamber length. To verify the feasibility of the collaborative optimization method, the nozzle was fabricated via 3D printing, and the simulation model was verified by testing. This study provides support to the development of design theory for self-oscillating pulsed cavitation jet nozzles.