Experimental study on flow characteristics of cavitation bubbles in underwater vertical movement of double vehicles

The cavitation generated during the water-exit process of the vehicle will have a great influence on the water exit attitude and stability of the vehicle. At present, the research on the cavitation flow mainly focuses on the single vehicle, and there is little research on the cavitation flow during the water-exit process of the double vehicles. However, in practical applications, it often happens that the double vehicles emerge from the water at different timings. Therefore, it is necessary to study the flow characteristics of the cavitation of the vehicles. In this paper, a set of underwater vertical launching experiment device of double vehicles under decompression condition is designed. Based on this device, different time sequence water-out experiments of the vehicles are carried out, and multiple high-speed cameras are used to record the whole process of the vehicles from different angles. The effect of launch velocity, environmental pressure, and lateral and vertical distances on cavitation morphological changes and sizes are explored. Studies have shown that there will be a certain degree of interference between the two vehicles during the water-exit process. When the launch speed increases and the environmental pressure decreases, the size of the cavitation when the double vehicles exit the water will increase greatly, and gradually move closer to the single vehicle; When the lateral and vertical distances increase, the interference between the vehicles will be weakened.