Impact of the inclined wall on the bubble dynamics within confined spaces

The present paper systematically investigates the bubble dynamics near the inclined wall within confined spaces. Based on the high-speed photography experiments, the typical phenomena of the bubble collapse jet, centroid motion, and splitting near the inclined walls are observed, and the effects of the bubble position and wall parameters on the bubble collapse dynamics are quantitatively analyzed. Based on the conformal transformation and the image method, a theoretical model of the bubble Kelvin impulse near an inclined wall within confined spaces is established. A quantitative analysis of Kelvin impulse and the Bjerknes force is conducted, mutually validating the observed experimental phenomena. The results show that the bubble splitting process varies from symmetrical splitting to asymmetrical splitting, and the jet always points toward the adjacent flat wall. In addition, both the displacement and direction of the bubble centroid motion closely correspond to variations of the Kelvin impulse, revealing that the angles of the inclined walls influence the bubble migration.