Experimental investigation of bubble dynamics near a double-layer plate with a circular hole

In this paper, to explore the bubble characteristics near a damaged double-layer structure, a simplified model of a double-layer plate with a circular hole was established. By using an electric spark-generated bubble and a mini-charge explosion-generated bubble, systematic experimental research on the bubble dynamics near the double-layer plate with a circular hole was carried out in a water tank. The diameter of the circular hole, the vertical distance between the two layers, and the stand-off distance between the bubble centre and circular hole centre are the main variables in studying the bubble dynamics. According to the detailed characteristics of inrushing bubble and external bubble, bubble morphology was divided into five categories. Meanwhile, the pressure history for different variables was recorded by using a pressure transducer. By analysing the peak pressures and the impulse induced by different phases of bubble motion, the mechanism and the quantitative analysis of the bubble load near the double-layer plate with a circular hole were obtained. •The bubble shape near a double-layer plate with a circular hole was divided into five types.•Quantitative law of the bubble load near a double-layer plate with a circular hole was obtained.•There is a critical distance parameter γfCR to separate the bubble load in the time series.