Meshing impact on numerical simulation of marine systems performance

In this paper, meshing impact on numerical simulation of marine systems is investigated. Different mesh topologies, meshing spacing, meshing refining area are discussed. Different shaped bodies such as ball, AUV and complicated motion such as propeller rotating are simulated with compared meshes in the paper. And its converging time, solution accuracy, and local domain flow characters are compared in detail. The research results of mesh refining area showed that a mesh refining area near the stern is more important than that near the bow, although there are large pressure gradients at both areas. In regards to the necessary of boundary layer mesh, we find out that for a translational motion of a marine system such as surge, sway and heave, the near wall prismatic layer mesh is necessary. And the sensitivity of numerical accuracy to the spacing of the first grid point away from the wall and numbers of layers of the near wall are discussed. While for a rotational motion, such as propeller motion, numerical calculation showed that there is not necessary to construct a boundary layer mesh in the near wall.