The distribution of pressure coefficient formed when the fluid contacts with the kayak oar blade is not been studied extensively. The CFD technique was employed to calculate pressure coefficient distribution on the front and rear faces of oar blade resulting from the numerical resolution equations of the flow around the oar blade in the steady flow conditions (4 m/s) for three angular orientations of the oar (45°, 90°, 135°) with main flow. A three-dimensional (3D) geometric model of oar blade was modeled and the kappa-epsilon turbulence model was applied to compute the flow around the oar. The main results reported that, under steady state flow conditions, the drag coefficient (Cd = 2.01 for 4 m/s) at 90° orientation has the similar evolution for the different oar blade orientation to the direction of the flow. This is valid when the orientation of the blade is perpendicular to the direction of the flow. Results indicated that the angle of oar strongly influenced the Cd with maximum values for 90° angle of the oar. Moreover, the distribution of the pressure is different for the internal and external edges depending upon oar angle. Finally, the difference of negative pressure coefficient Cp in the rear side and the positive Cp in the front side, contributes toward propulsive force. The results indicate that CFD can be considered an interesting new approach for pressure coefficient calculation on kayak oar blade. The CFD approach could be a useful tool to evaluate the effects of different blade designs on the oar forces and consequently on the boat propulsion contributing toward the design improvement in future oar models. The dependence of variation of pressure coefficient on the angular position of oar with respect to flow direction gives valuable dynamic information, which can be used during training for kayak competition.
Alexandra Laurent and Annie Rouard are with the Sport Science Department, University of Savoie, Chambery, France. Vishvesh-war R. Mantha is with the Engineering Department, University of Trás-os-Montes-e-Alto Douro, Vila Real, Portugal, and with the Research Centre in Sports, Health and Human Development (CIDESD), Vila Real, Portugal. Daniel A. Marinho is with the Research Centre in Sports, Health and Human Development (CIDESD), Vila Real, Portugal, and with the Department of Sport Sciences, University of Beira Interior, Covilhã, Portugal. Antonio J. Silva is with the Engineering Department and with the Department of Sport Sciences, Exercise and Health, University of Trás-os-Montes-e-Alto Douro, Vila Real, Portugal. Abel I. Rouboa (Corresponding Author) is with the Engineering Department, University of Trás-os-Montes-e-Alto Douro, Vila Real, Portugal. the Research Centre and Technologies of Agro-Environment and Biological Sciences (CITAB), Vila Real, Portugal. and the Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, PA.