An experimental study on water entry of horizontal cylinders

Complex hydrodynamics of a circular cylinder entering into water horizontally for low Froude numbers is experimentally studied. A high-speed digital video camera system is used to record the water entry process. The emphasis of this study is to investigate the three-dimensional effect on the water entry of the horizontal cylinders. A new experimental setup is built for this purpose and great effort is put on taking high quality pictures of the free surfaces. In the experiment four length to diameter ratios, two cylinder-water density ratios, and two release heights are investigated. For comparison, experiment with a sphere is also carried out. Quantitative analysis is performed based on the digital video images and the results are presented. The results obtained from this study can be used not only for understanding the physics but also for the purpose of validation of numerical models.