Existing theoretical and experimental work relating to two-dimensional mast/sail geometry of yachts is reviewed but no data is found about the windsurf shape. Seven different mast/sail configurations are modelled using the finite-volume package CFDACE. A turbulence module based on the standard k-e model is used over an unstructured triangular mesh, after a validation was done over experimental data.
An air flow with Reynolds number 1.8E6 is simulated over a windsurf sail section of mean line NACA 6-series (a=0.1 CLi=1.4) with and without mast on the leading edge. Three new mast configurations are also tested. The lift and drag coefficients for a varying angle of attack were calculated. However, the results are found to be best presented and best understood by means of graphs driving and heeling force for different angles of attack for a specific downwind course. The maximum driving force is increased by 7.4% over the actual mast used in windsurfing as well as the driving force/heeling force ratio. This ratio is a more accurate indicator of the efficiency of the sail than the typical lift/drag ratio.