Handling of Grid Deformation as Well as Sinkage and Trim of a Ship in Finflo-Ship

摘要

FINFLO-SHIP is a Reynolds Averaged Navier-Stokes flow solver specifically designed for calculating incompressible flows around ship hulls. The flow solver applies structured grids with a deforming water and air interface, the free-surface, and an accordingly deforming grid. This report describes the method applied in the grid deformation. The basic method is algebraic and quite simple. The method cannot, however, guarantee that the grid remains regular. Therefore, an elliptic grid resolver based on the Laplace equation is included. The flow solver is also able to take into account the sinkage and trim of the ship. The method applied for the calculation of sinkage and trim is also included. The method is simply based on the force and moment balance of the ship. The force and moment coefficients are obtained from the FINFLO-SHIP kernel. If the force or moment balance is not fulfilled during the calculation, then sinkage and trim are corrected accordingly.