## OPTIMAL SAILOR POSITION ON AN OLYMPIC DINGHY

 dc.contributor.author Pennanen, Mikka dc.contributor.department Chalmers tekniska högskola / Institutionen för sjöfart och marin teknik sv dc.contributor.department Chalmers University of Technology / Department of Shipping and Marine Technology en dc.date.accessioned 2019-07-03T14:27:06Z dc.date.available 2019-07-03T14:27:06Z dc.date.issued 2016 dc.description.abstract As the Laser Olympic dinghy is one of the highest level sail racing classes in the world, there is an interest in obtaining scientific facts around the tons of experience that already exist. For this reason, a numerical investigation was carried out to find the optimum heel and trim angles for upwind sailing. Flat water was assumed. Systematic Computational Fluid Dynamics (CFD) Simulations were carried out to find the optimum trim versus heel at speeds of two, three, four and five knots. During these computations the leeway was fixed for each speed. The leeway angles were estimated using the resistance results obtained from the tank tests and foil theory. A special purpose VPP was developed accepting CFD results at the given speeds as input for the hydrodynamic forces, while the aerodynamic forces were obtained using Hazen’s empirical model. The output from the program was the true wind speed required to achieve the target speed at 45 degrees true wind angle. By systematic variation of the sailor’s position the optimum heel (and the corresponding trim) was obtained at the minimum required wind speed. The reason for developing this unconventional VPP was to avoid interpolation between the speeds computed by CFD. Since the resistance/speed relation is very non-linear interpolation would have been too approximate for finding the rather flat heel/trim optima. The computational techniques and the optimum heel and trim angles of the dinghy will be reported in this thesis. In the course of the computations several interesting flow phenomena were investigated, such as the interactions between the centreboard and the rudder, and between the hull and the appendages. These by-products will be briefly reported in the Conclusions and Future Work –chapter. dc.identifier.uri https://hdl.handle.net/20.500.12380/248456 dc.language.iso eng dc.relation.ispartofseries Report. X - Department of Shipping and Marine Technology, Chalmers University of Technology, Göteborg, Sweden dc.setspec.uppsok Technology dc.subject Maskinteknik dc.subject Farkostteknik dc.subject Transport dc.subject Mechanical Engineering dc.subject Vehicle Engineering dc.subject Transport dc.title OPTIMAL SAILOR POSITION ON AN OLYMPIC DINGHY dc.type.degree Examensarbete för masterexamen sv dc.type.degree Master Thesis en dc.type.uppsok H local.programme Naval architecture and ocean engineering (MPNAV), MSc