Evaluation of Smooth Particle Hydrodynamic Methods for the Simulation of Helicopter Ditching

The presented activities were performed within the GARTEUR Action Group AG15 "Improvement of SPH methods for application to helicopter ditching" that aimed at assessing analytical tools for modelling helicopter impacts on water, with a specific emphasis for the Smooth Particle Hydrodynamic (SPH) formulation. In a first step, the vertical impact on water of simple rigid shapes at various velocities was simulated and compared to test results generated by Politecnico Di Milano. Simulations proved that the order of magnitude of the acceleration and pressure time histories could be very satisfactorily predicted. In a second step, the simulation of a simplified full-scale helicopter ditching was conducted and compared to results coming from an analytical code based on hydrodynamic equations. Though variable agreement was observed between the numerical and analytical data according to the simulated configuration, works however proved that the SPH method could be run over large run times, without numerical instabilities, thus highlighting one significant interest of such modeling method compared to classical Finite-Element solutions.