Kayak blade–hull interactions: A body force approach for self-propelled simulations. (March 2014)

• Record Type: Journal Article
• Authors: Banks, Joseph; Phillips, Alexander B; Turnock, Stephen R; Hudson, Dominic A; Taunton, Dominic J
• Is Part Of: Proceedings of the Institution of Mechanical Engineers. Volume 228:Number 1(2014:Mar.)
• Page Start: 49
• Page End: 60
• Publication Date: 2014-03
• Subjects: Kayak -- paddle -- computational fluid dynamics -- unsteady flow -- paddle–hull interaction -- performance; Sports sciences -- Periodicals; Sporting goods -- Design and construction -- Periodicals; Sports -- Technological innovations -- Periodicals; Biomechanics -- Periodicals; 613.71
• DOI: 10.1177/1754337113493847
• Languages: English
• ISSNs: 1754-3371

Abstract

A sprint kayak experiences an unsteady flow regime due to the local influence of the paddle. However, kayak designs are usually optimised for steady-state, naked hull resistance. To determine whether unsteady paddle effects need to be included in kayak design, the hydrodynamic interactions between a kayak paddle and a hull are assessed using computational fluid dynamics. A body force model of a drag-based paddle stroke is developed using a blade element approach and validated against experimental data. This allows the paddle-induced local velocities to be simulated without the need to fully resolve the detailed flow around a moving paddle geometry. The increase in computational cost, compared to the naked hull simulation, is 8%. A case study investigating the impact of different paddle techniques on the hydrodynamic forces acting on a self-propelled kayak is conducted. A 0.23% difference in self-propelled resistance was observed, while an estimated 0.5% additional increase can be attributed to paddle-induced draught increases. An estimate of small changes in resistance on race times indicates that reductions of even a fraction of a percent are worth pursuing, indicating that the developed methodology may provide a useful design tool in the future.