Experimental investigation into low-velocity water entry of cylinder structure

The process of low-velocity water entry is utilized on a large scale for the military and engineering purposes. However, there are rarely systematic experimental investigations into the low-velocity water entry of cylinder structure for reference. In order to obtain typical phenomena and relevant laws, we design a set of experimental facilities with adjustable parameters and better repeatability to study this process with a high-speed photography system. The influences of cylinder radius, initial velocity and entry angle on the process of lowvelocity water entry are tested. Results show that six typical phases exist in this process: structure submersion,necking, cavity formation, cavity abscission, spray at the free surface and jet formation. Three factors mentioned above are key parameters and influence the process in different degrees, and some laws obtained in this paper have a reasonable agreement with the theoretical results. Our results provide references for the relevant numerical researches and engineering applications.