Analysis of the hydrodynamic performance of three- and four-fin surfboards using computational fluid dynamics

Abstract

This study investigates the hydrodynamic performance of three- and four-fin surfboard configurations using the computational fluid dynamics (CFD)/CFX approach. CFD models of three- and four-fin configurations were setup inside a rectangular domain using CFX meshing. Comparisons of performance were evaluated by analysing both lift and drag coefficients for each fin system as a function of the angle of incidence at various speeds. The two-equation k-ॉ turbulence model was used as the base for simulations of flow velocities of 3, 5, 7 and 10 m/s. In addition the seven-equation Reynolds stress (RSM) turbulence model was also employed for flow velocities of 10 and 25 m/s in order to compare the predictions of the k-ॉ turbulence model. Results demonstrated that the maximum lift for the three-fin configuration occurred at a smaller angle of incidence than for the four-fin design. However, the magnitude of maximum lift was the same for both designs under the operating conditions considered in this study. These results imply that if a surfer desires a greater degree of manoeuvrability (ideal in regular surfing), then the three-fin configuration would be more appropriate in comparison to the four-fin configuration. This is because the three-fin design is more efficient at generating lift during smaller angles of attack compared to the four-fin design. However, if stability and speed in the surfboard is preferred (favourable in big wave surfing), then the four-fin configuration would be more suitable owing to less lift and drag at smaller incidence angles.

Keywords:

• Surfboards
• Fins
• Hydrodynamics
• CFX
• ANSYS
• performance

Additional information

Notes on contributors

P Gudimetla

Dr Prasad Gudimetla (PhD) is a lecturer in the School of Engineering Systems. He has been working at the interface of mechanical, manufacturing and medical engineering for the last 10 years, and his research interests are finite element modelling and simulation of structures and fluids, and non-linear analysis.

N Kelson

Dr Neil Kelson (BMath, GDipEd, MInfTech, PhD) is a Senior Research Support Specialist in the High Performance Computing and Research Support Group, Division of Teaching, Information and Learning Support, Queensland University of Technology. Neil’s research and teaching interests are mainly in the areas of engineering applications of computational fluid dynamics (CFD), boundary layer theory, and high performance parallel and distributed scientific programming.

B El-Atm

Billy El-Atm is a graduate mechanical engineer who now works for a surfing company in Queensland. The work reported in this paper was part of his undergraduate thesis.