DEVELOPMENT OF A MULTI-PURPOSE VELOCITY PREDICTION PROGRAM FOR SAILING YACHTS
Monday 22nd July 2013
This thesis aims at the development of a Velocity Prediction Program (VPP) able to analyse the sailing yachts that fall into the Delft Systematic Hull Series ranges. Over the last decade, the use of VPP for the analysis of yacht performance has gained a lot of popularity. This is due to the lower impact in the budget (both in terms of time and money) in a very competitive field such as yacht racing, where important decisions need to be made in small amounts of time. The inputs of the VPP are the boat geometry and the weather conditions in terms of wind speed and the angle between the boat and the wind direction, while its output is the maximum boat speed achievable by the boat in the given conditions. This speed is computed solving the equilibrium equations between the aerodynamic and hydrodynamic forces and moments. Two VPP models have been implemented: the first one was started at the Yacht and Superyacht Research Group at the Newcastle University (UK) and uses an iterative process to find the solution, whereas the second one solves the problem using an optimization algorithm. The second model entirely developed during this thesis improved the performance in terms of execution time and precision. To show how a VPP can also be used in the yacht design process, for example to predict the performance as a function of some geometrical parameters, different types of keels were tested to find the one giving the best performance. Finally comparisons between numerical and experimental data have been made to assess the accuracy of the numerical solutions.