Dynamic characteristics of a single bubble collapsing near an angular wall

Cavitation is easily activated by sudden changes in velocity and pressure in the liquid surrounding bubbles in narrow spaces formed by angular walls. In this study, the collapsing dynamics of a single bubble around angled walls with an inferior angle are investigated through the high-speed imaging system and the jet prediction model. At symmetrical and asymmetrical positions relative to the angular wall, the influence of the relative position of the bubble-wall vertex on collapse dynamics is analyzed, including the morphology, jet direction and intensity, and the bubble's oscillation period. The jet intensity distribution and the directional sensitivity at different included wall angles are studied. The results indicate that the collapse jet can be categorized into four types: wide, triangular, elongated, and inapparent. As the included wall angle decreases, the extension effect of the angular wall on the oscillation period increases significantly, with the extension index exceeding 1.7. The Kelvin impulse effectively predicts the jet direction for different included angles. The jet intensity reaches its maximum when the bubble approaches the wall, while the jet direction sensitivity is highest near the angle bisector.