Simulations of Hydro-elastic Impacts Using a Parallel SPH Model Available to Purchase

Sloshing-induced impact loads on tank walls of LNG vessels involve extremely complex physical phenomena such as compressible multiphase flow, hydro-elasticity, not to mention transition phases. These phenomena are a possible source of large local pressures. As an international recognised expert in LNG tank design, Gaztransport & Technigaz (GTT) is involved in various R&D projects linked with its core technology and related innovations. In this context, GTT funds specific research and development programs, especially in the domain of hydro-elasticity, at Ecole Centrale Nantes and its spin-off HydrOcean, with the aim to improve the understanding of the very complex phenomena involved during fluid impact on tank walls. This can subsequently lead to improvements in the methodology for sloshing assessment in LNG tanks. The work presented in this paper started with a PhD Thesis (GTT / ECN) dedicated to the development of a Smoothed Particle Hydrodynamics (SPH) solver able to simulate hydro-elastic impacts with strong fluid/structure coupling. Further developments have been made to integrate the fluid/structure SPH solver in an industrial SPH platform named SPH-Flow. These developments have mainly focused on the parallelisation of the fluid/structure solver and the implementation of solutions to avoid so-called Tensile Instability. They enable the simulation of liquid impacts on complex structures like MarkIII or NO96 containment systems. The paper first describes the theoretical core of the SPH fluid/structure solver. Various academic test cases are presented for validation of the recently implemented SPH structural model such as the free vibration of a beam and the wave propagation through a heterogeneous material. Recent developments on the parallelisation and solutions implemented to avoid Tensile Instability are described. The final validation case allows a comparison of the results of the fluid / structure SPH solver with analytical model results on a deformable beam wedge impacting the free surface at very high velocity. This last test case highlights the interest of the strong fluid / structure coupling developed.