Deep Dive: How Competitive Divers Use the Rip Entry to Reduce Splash

Competitive divers achieve much higher scores when they perform a splash-less entry. To accomplish this consistently they perform the rip entry maneuver by rolling their body forward in a somersault immediately after impact. This dynamic shape change – from a slender to a bluff body after impact – separates them from previously studied entry bodies. A geometrically simplified diver model is designed to perform a passive roll after impact. Modifications to this model are made to control the rate of deformation after impact. Experiments capture the approach, impact, and underwater trajectory of the diver model with a high speed camera. The model's trajectory after impact is tracked to identify the time it takes for each model to complete its deformation. These trajectory results are fed into a direct Navier-Stokes multiphase immersed boundary solver to better understand the hydrodynamic force change caused by deformation. The splash is resolved using both experimental and computational methods to identify how a dynamic shape change after impact changes splash production. Multiple underwater trajectories are investigated to understand what aspects of the rip maneuver are most important to creating a splash-less entry event. The results will begin to explain how Olympic divers are able to enter the water without creating a splash and will inform on how they can more consistently achieve this goal.