Bubble dynamics and cavitation inception mechanism characterization in aviation fuel liquids via computer vision tools*

Aviation fuel cavitation inception mechanisms triggered by a single injected bubble are characterized in the diverging part of the converging-diverging nozzle using advanced computer vision (CV) algorithms. The gained CV blob statistics provided unprecedented quantitative data from non-intrusive imaging techniques, revealing valuable insights into the bubble spatial-temporal evolution, breakup dynamics, and cavitation inception mechanisms in fuel liquids. Two distinct constant velocities of the bubble before its breakup and the resulting voids cloud after the breakup are observed consistently, despite the rapid fluid velocity decrease in that range. We have characterized the initial bubble size role in the resulting void fraction variation, bubble breakup site, and its terminal velocity before the breakup. Additionally, We have defined a unique dimensionless number, distinguishing between the breakup dynamic parameters accounting for different fuel liquids and flow regimes. The obtained results shed some light on the dynamics of a group of nonspherical cavities and complex fuel cavitation mechanisms.