In competitive swimming the dolphin kick is performed after the start and after each turn in all four strokes. It is therefore a substantial part of the actual competition, and any insights that can aid the performance of the dolphin kick will aid the performance as a whole.An integrated approach is taken at the Flow Simulation and Analysis Group to further the understanding of the dolphin kick and swimming in general. The first step consists of laser body scans taken of Olympic athletes and kindly provided by USA Swimming. These laser body scans are then meshed into thousands of triangles, our unstructured triangular surface mesh, using the software GAMBIT. On average 20000 triangles are used, with finer triangles and denser packing used at areas of higher curvature.The next step is to import the surface mesh into the animation software Autodesk MAYA. A skeleton of interconnected rotational and translational joints is inserted into the surface and "attached" to it. This enables smooth animation of the surface or skin via manipulation of the joints. Then video footage, also provided by USA Swimming is used to create kinematics of the swimmers, with the aid of Russell Mark, the Biomechanics Coordinator of USA Swimming.The kinematics are then used with in-house viscous, incompressible, Cartesian grid based computational fluid dynamics code VICAR3D to produce fully dynamic simulations. The Cartesian grid that the body is immersed in (the virtual flume) consist of about 4-5 million mesh points. Simulations of this size take on the order of 20-30 days to complete 2-3 cycles (kicks). Current simulations run serially on 2.0 GHz AMD Opteron processors. As of yet, there is no air-water interface. Simulations of the arm during the backstroke are also currently running.
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