An enhanced fully-Lagrangian computational method is proposed for simulation of incompressible fluid-nonlinear structure interactions. The proposed computational method corresponds to an enhanced coupled SPH (Smoothed Particle Hydrodynamics)-based FSI (Fluid Structure Interaction) solver. Coupling is conducted between an enhanced Incompressible SPH (Shao and Lo, 2003) fluid model in the context of Newtonian mechanics with a structure model in the context of Hamiltonian mechanics. The structure model corresponds to the Hamiltonian structure model (Suzuki and Koshizuka, 2008), reformulated based on the SPH-based approximations of derivatives. The Enhanced ISPH-HSPH FSI solver is employed in simulations of a set of important benchmark tests. The results of simulations are subjected to both qualitative and quantitative verifications.
The dynamics of systems dominated by complex Fluid-Structure Interactions (FSI) are of substantial importance in a variety of fields in ocean engineering (e.g. wind induced waves interactions with onshore structures, hydrodynamic slamming loads on ship hulls, tsunami/storm surge impact on coastal facilities and etc.). With respect to the importance of the FSI problems, numerous efforts have been dedicated so far to the development of accurate, stable and consistent computational methods for reproducing such important phenomena.
In recent decades, Lagrangian grid-less numerical methods, so-called particle-based methods e.g. Smoothed Particle Hydrodynamics (SPH; Gingold and Monaghan, 1977; Lucy, 1977), have exposed great contributions in reproduction of many significant problems of fluid/structure dynamics related to ocean engineering. Following the successful applications of particle methods in fluid/solid continuum mechanics, several researchers have targeted developing FSI solvers by taking advantage of appropriate formulations of particle methods. In this regard, many researchers have shown interest in coupled methods, taking advantages of combinations of the fully Lagrangian formulations of particle methods along with fully-developed configurations of other computational frameworks, e.g. coupled SPH-Discrete Element Method (Wu et al., 2016), coupled SPH Shell-Boundary Element Method (Zhang et al., 2013) and coupled SPH-Element (Yang et al., 2012; Li et al., 2015; Fourey et al., 2017; Siemann et al., 2017).