CFD and Experimental Performance Evaluation of Grooved Fins for Surfboards

Surfing is an iconic sport that was included in the 2020 Tokyo Olympics. There are several variables that can influence the surfing performance on waves, e.g. surfboard, fins and surfer. In terms of speed and stability during maneuvering, surfboard fins should be designed to minimize the drag force applied by water and maintaining a reasonable lift force for large angles of attack during a sudden change in direction.<br/>In this presentation, we discuss the use of computational fluid dynamics (CFD) simulation to study the performance of surfboard fins with topological features (grooves) compared to conventional fins. The simulation examined the performance of each type of fins in terms of hydrodynamic forces and their behavior for several angles of attack. Our virtual experiments demonstrated that the introduction of grooves on the surface of the fins reduced the drag, which would translate into an increase in surfing performance, i.e. speed.<br/>The increase in performance was confirmed in experimental studies on ocean waves involving instrumented surfers on instrumented surfboards. Fins with and without grooves were manufactured in a layered nylon-carbon fibre composite materials using a 3D printing process. The performance data demonstrated that the introduction of grooves resulted in increased surfing performance (speed) compared to conventional fins.