TOWARD WALL MODELING IN CARTESIAN GRID SOLVER USING OVERSET GRID TECHNIQUE FOR SHIP HYDRODYNAMICS

摘要

A Cartesian grid solver is coupled with an orthogonal curvilinear grid solver using overset grid interpolation and a coupled pressure Poisson solver. It aims at resolving the boundary layer on the body surface effectively. SUGGAR code, an overset grid assembly program, provides overset grid information of a Cartesian background grid and a thin orthogonal body-fitted grid to resolve the boundary layer on the surface. The overset grid information is used to interpolate velocity, pressure, turbulence quantities, and level set function. A coupled pressure Poisson equation is solved using PETSc. The coupled curvilinear/Cartesian grid solver has been applied to two-phase turbulent flows past a circular cylinder and has shown good agreement with the experimental data and the LES results in the literature. The solver is being applied to a free surface flow around Wigley's parabolic hull form at Re = 3.4×10~6 and Fr = 0.25. The numerical results are promising compared to an experimental result of wave elevations at the same Fr.