Hull Form Optimization of Performance Characteristics of Turkish Gulets for Charter

Turkish Gulets are motor-sailors that are still being built using wooden boatbuilding traditional construction in the Aegean and Mediterranean as well as being built using steel and cold moulded techniques. They are typical of the craft used for skippered charter tours in the region and exhibit good seakeeping in the shorter steep sea of the Mediterranean and also for manoeuvring in port and in anchorages. Usually this performance is at the cost of resistance. Sailing performance and stability are surprisingly not considered due to the large beams. The hull forms of two typical gulets are used to examine the stability, resistance and coupled heave and pitch. A multi-objective evolutionary optimization methodology is used to investigate the performance of the three objectives. The evaluation of resistance uses a transom modified Michell theory in keeping with the smaller L/B ratios and large transoms of many of these vessel types. Seakeeping is evaluated using a strip motion program and the stability curve is used to provide a stability index. The multi-objective analysis is based on the optimization capabilities of genetic algorithms. Evolutionary algorithms are stochastic in nature and follow the Darwinian principle of survival of the fittest. From a given population of hull candidates, those hulls that are “fitter” by having better resistance, seakeeping and stability are selected to generate a new population. Over the course of many generations, the hulls are optimized to provide better performance. Each of the objectives requires an index to measure the performance of the candidate.