Simulation Study on Oscillating Cavitation Nozzle for Cleaning Based on FLUENT

Abstract: Based on the basic theory of fluid dynamics and Fluent software, numeric simulation of self-excited oscillating cavitation jet nozzle for cleaning was carried out. The flow field characteristics within tubular organ cavitation nozzle is studied. By numerical simulation, the exit velocity, velocity vector distribution, pressure inside the nozzle as well as static pressure distribution were obtained. The simulation results show that there is a maximum speed at cylindric section inside the cavitation nozzle. When water jet getting into the cylindric section of the cavitation nozzle, there is a significant zone with high negative pressure.Also there is a obvious zone with negative pressure at the outlet end. When the pressure is below the saturation vapor pressure of the liquid, cavitation bubbles occured. Therefore the cavitating water jet was generated. The simulation results also show that there is a higher negative pressure inside the nozzle region when the nozzle inlet diameter Ds = 6 mm, the diameter of the cavity D = 3 mm, the diameter of the cylindric section d = 1.8mm, the resonator length L = 6.2 mm, spread angleα= 60 °, the length of the cylindric segment s = 6 mm, Thererfore it is beneficial effect for the cavitation generating.