Computer Integrated Design of Surfboard-Fins to Improve Turning Ability With Drag Force Reduction

This paper describes the design and development of surfboard-fins as products for marine sports. The purpose of the research is to improve turning ability by reducing drag force on the fins. Design modification was conducted, based on conventional fins, to increase turning ability and lower drag force. Three modified center-fins and three modified side-fins were selected. The design process involved 3D-CAD fin configuration models created with ProENGINEER Wildfire and utilized computational fluid dynamics from 3D-CAD data. Solid forms, which are required in this study since fin configuration is streamlined, are difficult to use in 3D-CAD software. Therefore, a surface element software (NURBS) developed by a propeller maker in Japan was used and the fins were converted into solid forms. After producing the fin models, the performance of factors such as turning ability and drag force were calculated using computational fluid dynamics. A flow experiment was conducted using a flow water tank in Western Hiroshima Prefecture Industrial Research Institute. This report commences with an explanation of the modifications on the fin models to improve turning ability and lower the drag force. It is then followed by the flow analysis using computational fluid dynamics software and the flow experimental results.