A PIV-based method for estimating slamming loads during water entry of rigid bodies

Hydrodynamic impact of bodies onto the water surface is a problem of great importance in the design of off-shore and naval structures (wave energy converters, off-shore platforms, high-speed boats, etc). Classical measurement techniques, namely pressure sensors, present major drawbacks in the determination of impact loads because of their intrusive nature. In this paper, we propose a method to determine the impact loads on rigid bodies during water entry, based on high-speed particle image velocimetry. The method consists of two steps: firstly, an automated procedure is developed to determine the velocity field from high-speed images during water impact. Secondly, the unsteady pressure field is estimated from the velocity fields, using a Poisson-based solver. The method is validated on a rigid wedge slamming experiment and the results are compared with results from computational fluid dynamics simulations (performed with the software LS-Dyna) and from the literature.