Experimental Research on the Electric Spark Bubble Load Characteristics under the Oblique 45 Degree Curved Surface Boundary

• Published in: Journal of marine science and engineering 2021-01, Vol.9 (1), p.32
• Main Authors: Ma, Chunlong, Shi, Dongyan, Li, Chao, Wang, Mengnan, He, Dongze
• Format: Article
• Language: English
• Subjects: ABAQUS/Explicit; Ablation; Bubbles; Cameras; Cavitation; cavitation bubble pulse load; cavitation bubble shape; Electric discharges; Electric sparks; Experimental research; Experiments; Explosions; Finite element method; High speed cameras; Laboratory experimentation; Lasers; Load; Marine invertebrates; Mushrooms; oblique 45-degree boundary; Parameters; Pressure sensors; Pulsation; Research methodology; Sensors; Shape; Shock loads; Shock waves
• ISSN: 2077-1312; 2077-1312
• DOI: 10.3390/jmse9010032

In order to study the influence of the pressure load generated during the pulsation of cavitation bubbles on the oblique 45-degree curved surface boundary. The curved surface boundaries have different curvatures. This study also designs a multi-angle bracket to make the oblique boundary oblique 45 degrees. This research uses high-voltage electric discharge to generate electric spark bubbles, which act as cavitation bubbles. When the explosion source is at different distances from the oblique 45-degree boundary, a high-speed camera is used to capture the pulsation process of electric spark bubbles. A pressure sensor is used to measure the pulsating load of the electric spark bubbles on the oblique 45-degree boundary during the pulsation process. In this study, we use the dimensionless parameter ζ to represent the curvature of the oblique 45-degree boundary. The dimensionless parameter γ is used to represent the shortest distance between the explosion source and the oblique 45-degree boundary. It is found through experiments that the oscillation characteristics and pulsating load of electric spark bubbles will be affected by ζ and γ. This study summarized six types of unique bubble pulse shapes from 44 groups of experiments. They are “mushroom shape without jet”, “mound shape with jet”, “jellyfish shape with jet”, “oval shape with jet”, “drop shape without jet”, and “spherical shape without jet”. In this paper, the ABAQUS/Explicit is used to simulate the ring-shaped bubble that is not clearly captured by the high-speed camera. Finally, the study summarizes the shock wave load generated during the explosion, the first pulsation load, and the second pulsation load of electric spark bubbles, and finds an obvious overall trend of change.