Research on modified cavitation model for self-excited oscillation pulsed jet nozzle

Based on the mechanism of the cavitation effect in the self-excited oscillation pulsed jet nozzle, a modified cavitation model is proposed for improving the precision of the simulation, which considers the influence of Reynolds shear stress, the viscous shear stress and the turbulent pressure fluctuations existed in the shear layer on the vapor pressure. The modified cavitation model is hooked in the Fluent through the user defined function (UDF) to define the vapor pressure property which plays a role of criterion for cavitation. The fluctuation, frequency and magnitude distribution of the velocity at the outlet of the nozzle are analyzed and compared with the corresponding results obtained by using the original cavitation model. It is observed that the results obtained by the modified model are more consistent with the actual working situation of the nozzle. Finally, the effect of the inlet pressure on the occurrence of the cavitaion is investigated for exploring the relationship of the cavitation chance and the factors considered in the modified cavitation.