Maneuvering Simulations for Ships and Sailing Yachts using FRIENDSHIP-Equilibrium as an Open Modular Workbench

摘要

An open modular workbench called FRIENDSHIP-Equilibrium has been developed for the analysis of stationary and instationary modes of motion. FRIENDSHIP-Equilibrium offers an integration environment and suitable algorithms for determining the equilibrium of forces and moments acting on ships and yachts, following a force model approach. In the stationary mode the steady state properties of the vessel are determined (hydrostatics, VPP) while in the instationary mode the accelerated rigid body motions are computed (maneuvering motions). The equations of motions may be solved by means of various time integration methods one of which being an advanced time-step adapting Runge-Kutta algorithm. The functionality comprises the computation of added mass and damping as needed for time simulations. Special consideration is given to the aero- and hydrodynamics of sailing. The program therefore also constitutes a refined Velocity Prediction Program. Within the paper various maneuvering situations are presented for both a conventional cargo ship and a contemporary IMS yacht. The examples serve to show the applicability of the approach and to illustrate the usage of the tool. Attention will also be given to IT integration.