Modelling ricochet of a cylinder on water using ALE and SPH methods

The ricochet means the rebound off a surface and is a very important scenario in engineering applications. The specific case of an impact of a solid steel body on a water surface has been chosen for the ricochet example. This solid body hits the water surface with a certain velocity and angle and their dependency on the ricochet behaviour is of interest. This impact scenario can be further developed for more complex impact scenarios, like the ditching of aeroplanes, and has been extensively studied in the past. Due to that fact, it was decided to compare the two numerical analyses with each other; SPH in the internal developed code MCM at Cranfield University with the ALE method in the commercial programme LS-Dyna. The early state of the development was the reason that a 2D model was developed in the 3D solver and therefore verification with another method crucial. Therefore the two simulations were set up and the ricochet behaviour investigated. In contrast to the experimental results, these results demonstrate that independent of the numerical method, both models show an unexpected overproduction of ricochet at higher impact velocities, but agree in their over prediction. The benefits arising out of the collaborative approach of SPH and ALE to describe a problem are presented.