One of the most important tools in today’s sailing yacht design is the Velocity Prediction Program (VPP). VPPs calculate boat speed from the equilibrium of aero and hydrodynamic flow forces. Consequently their accuracy is linked to the accuracy of the aero- and hydrodynamic data used to represent a yacht. These data are usually derived from experimental or CFD results and processed by means of linearization and interpolation to represents the actual sailing state of the yacht, this interpolation being a source of inaccuracy. Furthermore, viscosity related effects are often estimated by simplified theoretical or empirical models potentially neglecting complex physical phenomena. The paper proposes a method circumventing these inaccuracies. It is based on the idea to directly derive Sailing Yacht performance from a RANSE flow simulation. This is done by coupling the prediction of sail forces with the hydrodynamic forces calculated by the flow code and solving the resulting imbalance in the equations of motion in the RANSE solver. The paper discusses implementation steps for the inclusion of sail forces and body motion into the flow code as well as calculation and grid setup. Results of the method christened RVPP are shown for a generic yacht design and are compared with results from a classical VPP approach on the same design. The paper finishes with a discussion of the pros and cons of the method and an overview at future development steps of RVPP.

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