Influence of water quality on the tip vortex cavitation inception

Tip vortex cavitation (TVC) is an important type of cavitation. There is an urgent need for the accurate prediction of its inception condition. The water quality, i.e., the distribution of nuclei, is one of the main contributors to the TVC inception. Since there is no available cavitation model involving the effect of water quality, a new model suitable for TVC prediction is investigated based on the bubble dynamics. The migration and growth of nuclei are simulated in a tip vortex flow. An analytic method is developed to calculate the capture time of nuclei so that we can determine the critical nucleus in a vortex flow according to a filtering principle. The comparisons of the effect of water quality obtained in simulations and analytics are performed. It validates that the embodiment of water quality is rational and the analytical method is applicable for engineering purpose. Finally, the prediction model is quantitatively improved by considering the effect of water quality, and it is a new model for the prediction of tip vortex cavitation inception.