Pressure Pulses due to Bubble Cavitation Collapses on a NACA 0015 Hydrofoil

This paper presents an experimental method for studying erosive cavitation. Specifically, this study focuses on estimating the aggressiveness of the cavitating flow. The selected case study is a NACA 0015 hydrofoil tested under operating conditions with a zero angle of attack, a flow velocity of V = 8 m/s, and a cavitation number ratio of σ/σi = 0.97. The presented measurement techniques combine high-speed videos and computer vision techniques to provide a quantitative measurement of bubble cavitation dynamics and its main characteristics. The bubble dynamics observed experimentally were analyzed using a mathematical model. This allowed to estimate some bubble collapse characteristics strictly related to the cavitation erosive power but of too short duration to be captured in high-speed videos. Estimating these quantities allow to study the erosive cavitation locally and to evaluate the criticality of the collapse of each cavitating structure. The results provide valuable insight into the collapse characteristics of cavitation bubbles, paving the way for a deeper understanding of cavitation erosion.