Development of high performance sailcloth

The aim of this thesis is to develop a sailcloth having tubercule fabric constructions designed with a biomimetic approach that can reach higher speeds at the same wind intensity and under the same conditions to be used in cruising sails with. Within the scope of the presented thesis, alternative fabric designs with a structure similar to the fin of a humpback whale were developed, the aerodynamic performances of these fabric structures were measured by wind tunnel experiments, the fabric parameters affecting the aerodynamic performance were determined, the measurement results were analyzed and the relationships between fabric parameters and aerodynamic performance were investigated. Fabric surface index (YI), fabric static and kinetic friction coefficients were measured as fabric parameters affecting aerodynamic performance. Also a new method and the flexural index (EI) concept have been developed to measure the area increase due to wind pressure. The relationship between these four parameters and fabric aerodynamic performance was revealed by regression analysis. The regression model was verified by comparing the wind tunnel measurements and the values calculated from the model, and it was seen that the aerodynamic performance of the fabrics could be calculated with a 4% margin of error. Thus, a new, easy and practically applicable method has been developed as an alternative to wind tunnel tests, which are difficult to access and costly, to determine the aerodynamic performance of fabrics. Wind tunnel experiments suggested that the fabric with tubercule structure has a 10.3% higher aerodynamic performance; while the fabric with tubercle structure and woven with microfiber yarns has a 24.3% higher aerodynamic performance compared to the standard sail fabric. This results clearly show the effect of targeted tubercule structure and microfiber use on aerodynamic performance of the sailcloth.