Nucleation effects on tip vortex cavitation inception location

Nuclei, or microbubble, populations are inextricably linked to tip vortex cavitation (TVC) inception and dynamics. In order to gain a better quantitative understanding of this relationship, high-speed video measurements were taken in a cavitation tunnel of TVC inception locations about an elliptical hydrofoil in flows with mono- and polydisperse injected nuclei populations. Sample sizes of O(1000) were acquired. For both populations, inception occurred between 0.02 chord lengths upstream of the hydrofoil tip and about 2.1 chord lengths downstream along the cavity trajectory. However, inception location distribution varied significantly with nuclei population. This is explained by the higher concentrations of weaker nuclei in the monodisperse case, which increases the distance along the vortex within which nuclei are susceptible to cavitation. These results provide the foundation for studies on TVC dynamics and acoustics.