Numerical study on the water impact of 3D bodies by an explicit finite element method

Abstract

The hydrodynamic problem of the water impact of three-dimensional buoys is investigated by the explicit finite element method with an Arbitrary-Lagrangian Eulerian (ALE) solver. The fluid is solved by using an Eulerian formulation, while the structure is discretized by a Lagrangian approach, and a penalty coupling algorithm enables the interaction between the body and the fluids. The remap step in the ALE algorithm applies a donor cell+HIS (Half-Index-Shift) advection algorithm to update fluid velocity and history variables. The interface between the solid structure and the fluids is captured by Volume of Fluid method. Convergence studies are carried out for three dimensional hemisphere and cones with different deadrise angles. It is found that the mesh density of the impact domain is very important to the quality of the simulation results. The contact stiffness between the coupling nodes affects the local peak pressure values. The numerical calculations are validated by comparing with other available results, for both the drop cases and the ones with constant impact velocity.