When sailing upwind the fore sail is a flat and smaller Genoa and the fluid stream usually follows the sail surfaces. When sailing downwind the fore sails are the lighter, bigger and more deformable Gennaker and spinnaker and the fluid stream often shows large vortices and is highly turbulent. Thus, a fluid-structure interaction analysis on sails is much more complicated in the downwind case and must be modeled by a system of equations involving both the full Navier-Stokes equations for air and suitable membrane equations that properly describe the sail structures.

ACM ag Stefano Gattini