Investigation of Skirt Dynamics of Air Cushion Vehicles under Non-linear Wave Impact Using a SPH-FEM Model

This paper presents the use of a Computational Fluid Dynamics (CFD) tool to investigate the dynamics of the skirt system of an idealized Air Cushion Vehicle (ACV) under non-linear breaking wave impact. The fluid domain, includes water and pressurized air inside the ACV’s bag, is modeled using Smoothed Particle Hydrodynamics (SPH). To model the deformable structural domain, the Finite Element Method (FEM) is utilized. A validation case of flow inside a sloshing tank with a flexible wall is also presented to illustrate that the SPH-FEM model can solve problems involving complex free-surface flow interacting with structures under large deformation with good accuracy. Preliminary work toward application to ACV skirt dynamics is then presented. The results obtained suggest the SPH-FEM model can address many of the difficulties traditional meshed methods would encounter when attempting to simulate a breaking wave impact on a flexible structure thus providing a viable alternative for computer aided design of ACV skirt systems.