Large Eddy Simulation of Turbulent Flows Around Two Canoe Paddles

ABSTRACT: In competitive canoe racing, advances in hydrodynamic technologies are a driving force in improving performance. Reshaping the paddle is one way to accomplish this. Currently, there are many studies on hull design and biomechanical analysis, but few have taken on paddle shape optimization. In our work, we have analyzed two different canoe paddle designs, having straight and curved blades respectively, which are manufactured by GRB Newman Designs [1]. Based on video analysis of the sport and experiments performed with strain gauges and other measurement techniques, it was found that the propulsive forces generated by paddlers result in a Reynolds number of roughly 200,000 [2]. Using ANSYS Fluent, we can quantify the differences in hydrodynamic performance between curved and straight canoe paddles. Turbulence modeling, specifically, wall-modeled Large Eddy Simulation (WMLES), was adopted to analyze the fluid dynamics and compare the relative efficiency of these two paddle designs using high-performance computation (HPC). Analysis of a square cylinder was performed to demonstrate the capability of the model [3]. Following the validation study, the LES model was employed to assess the performance of a curved-blade canoe paddle against a straight-blade paddle. To predict the propulsive force that the paddle produces, an analysis of the catching (80°), and middle (90°) phases of the stroke was conducted. Fluid flow around the paddles exhibited significant differences in velocities and pressure near the tips of the blades. The following figures have been post-processed to help convey the difference in flow associated with the straight and curved blades at two different phases of a paddle stroke. The axes X, Y, and Z have been normalized by the blade width w. REFERENCES [1] https://www.grbnewmandesigns.com [2] Morgoch D. and Tullis S., 2011 “Force analysis of a sprint canoe blade”. Sports Engineering and Technology, 225:253-258 https://doi.org/10.1177/1754337111407793 [3] Saeedi M. and Wang B., 2016. “Large-eddy simulation of turbulent flow around a finite-height wall-mounted square cylinder within a thin boundary layer”. Flow Turbulence Combustion, 97:513–538. https://doi.org/10.1007/s10494-015-9700-7