Simulations of Breaking Wave Impacts On a Rigid Wall At Two Different Scales With a Two Phase Fluid Compressible SPH Model

After years of efforts (Deuff, 2007, Oger et al., 2009; Guilcher et al., 2010), HydrOcean and Ecole Centrale Nantes, supported by GTT, succeeded in the development of a SPH software gathering all functionalities for relevant simulations of sloshing impacts on membrane containment systems for LNG carriers. Based on Riemann solvers, SPH-Flow deals with two compressible fluids (liquid and gas) that interact with the impacted structure through a complete coupling. The liquid, the gas and the structure are modelled by different kinds of dedicated particles allowing sharp interfaces. An efficient parallelisation scheme enables to perform calculations with a sufficiently high density of particles to capture adequately the sharp impact pressure pulses. The development of the bi-fluid version led in a first stage to unstable solutions in the gaseous phase for pressures below the ullage pressure. This difficulty was presented in ISOPE 2010 (see Guilcher et al., 2010) and has been overcome since. Simulations of a unidirectional breaking wave impacting a rigid wall after propagating along a flume are presented in this paper. The physical phenomena involved in the last stage of the impacts are scrutinized and compared with experimental results from Sloshel project (see Lafeber et al., 2012b). A comparison between calculated results at full scale and at scale 1:6 is proposed. Conclusions about scaling in the context of wave impacts are given.