RESEARCH ON DYNAMICS OF THE CYLINDRICAL CAVITATION BUBBLE NEAR A RIGHT-ANGLE WALL BASED ON HIGH-SPEED PHOTOGRAPHY

The dynamics of cylindrical cavitation bubble near a right-angle wall are investigated based on the high-speed photography experiment. The cavitation bubble is induced by laser focusing and formed in the liquid environment between two parallel glass plates with a small spacing, thus having obvious cylindrical characteristics. By changing the dimensionless distance l^* between the cylindrical cavitation bubble and the right-angle wall vertex, and the position angle θ, the complete collapse behaviors and variation trends of the cylindrical cavitation bubble at the symmetric and asymmetric positions are investigated, respectively. The influence of the relative position between the cylindrical cavitation bubble and the right-angle wall on the bubble dynamics, such as the deformation of the cylindrical cavitation bubble wall, the movement distance and direction of the bubble centroid are revealed. The research results are as follows: During the collapse stage of the first period, the bubble surface on the side of the cylindrical cavitation bubble away from the wall will appear concavity, and gradually develop until the cylindrical cavitation bubble is divided into two parts. When the bubble is located at symmetrical positions, as the dimensionless distance l^* increases, the concave degree of the bubble surface is gradually weakened, and the moving distance of the bubble centroid during the collapse stage is gradually reduced. When the bubble is located at asymmetric positions, as the position angle θ decreases (for the situation of θ < 45°), the moving direction of the bubble centroid gradually changes from pointing to the vertex of the angled wall to pointing to the lower wall.