Density correction in smoothed particle hydrodynamics and SPH-FEM coupling method for FSI analysis

Abstract

In this dissertation, a new density correction method of smoothed particle hydrodynamics (SPH) is proposed to obtain reliable fluid pressure. Additionally, a new coupling method for the fluid-structure interaction (FSI) analysis is proposed using the smoothed particle hydrodynamics (SPH) and the finite element method (FEM). First, numerical methods to resolve unphysical density and pressure oscillations are suggested in which the unphysical density oscillations are mainly induced by particle inconsistency. Especially, the density dissipation problem that induces fluid pressure errors is effectively resolved. Second, numerical methods for the FSI analysis are proposed to evaluate the structural responses of elastic structures interacting fluids. To do so, a new coupling method for the FSI analysis is developed using the SPH and the FEM. Through the proposed method, the hydrodynamic loads acting on the elastic structures are exactly evaluated and the fluid flow characteristics induced by the dynamic response of the structure can be analyzed. Furthermore, the computational inefficiency in the simulations is effectively reduced by the proposed method. The proposed methods are applied to various engineering problems such as hydrostatic flow, sloshing flow, dynamics of the floating structure, and so on. Furthermore, the proposed method is demonstrated by comparison with experimental and theoretical results in various numerical examples.