Accurate and efficient hydrodynamic analysis of structures with sharp edges by the Extended Finite Element Method (XFEM): 2D studies

Achieving accurate numerical results of hydrodynamic loads based on the potential-flow theory is very challenging for structures with sharp edges, due to singular behavior local-flow velocities. In this paper, we introduce, perhaps first time in literature marine hydrodynamics, Extended Finite Element Method (XFEM) solve fluid–structure interaction problems involving edges structures. Compared conventional FEMs, basis functions are introduced XFEM through local construction shape finite elements. Four different FEM solvers, including linear and quadratic FEMs as well their corresponding versions enrichment by at implemented compared. To demonstrate accuracy efficiency XFEMs, a thin flat plate an infinite fluid domain forced heaving rectangle free surface, both two dimensions, will be studied. For plate, mesh convergence studies carried out velocity potential added mass, XFEMs show apparent advantages thanks enhancement edges. Three strategies also compared, suggestions made practical implementation XFEM. rectangle, 2nd order mean wave Our confirm previous conclusion that it not difficult model obtain convergent mass damping coefficients. However, when requiring computation components calculated via direct pressure integration, influence singularity significant, takes tremendously large number elements get results. On contrary, converge rapidly even coarse meshes, especially Unlike other methods decomposition dealing singularities, framework more flexible include approximations.