Vertical water entry cavity of cylinder body

Experimental studies of the vertical water-entry of cylinder bodies were conducted using high-speed camera to capture the splashes over the water surface and the subsurface cavity shapes. The cavities formation and stability were discussed for 140癱onical cylinder bodies fall into water freely. Experiment results show that the air cavity formed at very low entry speed, and lots of complicated flowing phenomena accompanied with the whole process of the formation, including splashes, cavity expand and cavity pinch-off. And the effects on the stability of the cavity due to the impact of tail were also discussed with vertical entry of the 140癱onical cylinder at an angle of attack, and the results reveal that the impacts on the cavity play different roles for stability of cavity at different stage of the whole process of formation. Finally, the effects on the cavity shapes and the pinch-off of vertical water-entry of right cylinder were conducted at various entry speeds. It shows that the cavity shapes and type of pinch-off are great depended on entry speed.