Experimental transient cavitation bubbles in a conical-frustum shaped tube

Abstract

Extreme flow acceleration in the water can induce large cavitation bubbles in the hydraulic machinery, and cause liquid column separations in the pipeline. The abrupt collapse of these large bubbles produces strong pressure oscillation and causes catastrophic destruction instantaneously. Considering the complexity of the shapes of pipelines in engineering, we experimentally study the transient bubble dynamics in a conical-frustum shaped tube by a modified tube-arrest method in the present paper. Three shapes of cavitation bubbles are observed during the transient processes: (A) conical-frustum shaped bubbles originated from the bottom; (B) hemispherical bubbles originated from the side wall; (C) conical-frustum shaped bubbles originated from the liquid bulk. It is seen that the locations of the cavitation bubbles strongly depend on the geometries and the surface roughness of the tube, and the nucleation status of the bulk liquid.

Collapsing behavior of spark-induced cavitation bubble in rigid tube

“…The results showed that the jet velocity of the bubbles is influenced by the liquid inertia on the bubble surface and is related to the bubble position and the inner diameter of the tube section. Wang et al, (2022) [35] considering the complex shape of tubes in engineering, the modified tube - arrest method was employed to investigate the transient cavitation bubble in a conical - frustum - shaped tube. Three morphologies of cavitation bubble generation were observed, and it was pointed out that the location and morphology of cavitation bubble strongly depended on the tube sizes and roughness of tube wall.…”