The Influence Analysis of Expansion Angle and Internal Fluid Cavitation Phenomena for Zoom Nozzle

The cavitating water jet is a new type jet with great potential and good efficiency, which has been applied widely in rock crushing, oil drilling, wastewater degradation, industrial cleaning and so on.Cavitating water jet cleaning technology was caused the attention in these years for good cleaning quality and cleaning speed, no environmental pollution, no corrosion of cleaning material etc. The simulation model of zoom nozzle was established in this paper. The numerical simulation of internal fluid for the zoom nozzle was completed with the different expansion angles by the fluent software. The results showed that the pressure near the transition area of the cylindrical section is so low that it’s easy to form the cavitation phenomenon; and in the different nozzle expansion angle, the change tendency of the fluid gas content is consistent; and with the nozzle expansion angle increasing, the distance between that emergence point of maximum cavitation rate and nozzle cylindrical section decreases continuously. Keywords-cavitating jet; zoom nozzle; cavitation; expansion angle; simulation