Abstract
A method to handle large amplitude ship motions in free surface viscous flows is presented. The method relies on dynamic overset grids to accommodate motions and single-phase level set to compute the free surface flow. Overset grid connectivity is found at run time using the code SUGGAR, allowing implicit coupling between fluid flow and body motions. Higher order solvers are used to compute mass and momentum conservation, as well as the level set function used to detect the air/water interface. Geometric/implicit reinitialization methods are used to maintain the level set function as a distance function. A six degree of freedom (6DOF) module was implemented that allows for explicit or implicit computation of predicted motions. Prescribed/predicted motions combinations are also possible, allowing for the simulation of towing tank experiments such as Planar Motion Mechanism (PMM) tests. These methods have been implemented in the code CFDShip-Iowa, version 4. We present code results for several problems including examples from the traditional areas of naval architecture of resistance and propulsion, seakeeping and maneuvering.