The main objective of the present work is to propose a methodology to evaluate the Directional Stability index of a displacement ship using Computational Fluid Dynamics to evaluate its linear hydrodynamic derivatives.
The first step is the review of the ship’s equations of motion, followed by the formulation of the straight-line stability problem, which depends basically on the evaluation of the ship’s linear hydrodynamic derivatives. After this, the experimental methods that are normally used to evaluate these characteristics during ship design are presented, since they will be simulated in a numerical environment.
Having reviewed the common experimental methods applied to determine the straight-line stability of a ship, the numerical code used to evaluate it in this work is presented, in order to show how the physical constitution of the experimental apparatus is adapted to a computational environment. Together with this will be presented the KVLCC2 model used or the computations, together with the numerical mesh where the computations were carried out. With this, it becomes possible to show the numerical results obtained in this work.
The last part of this paper consists in comparing the numerical results obtained in the step before with the Clarke statistical correlations in order to assess or not the accuracy of the methodology proposed.