Fish Kick

Bob Gillett

I am a swimming coach, with top level world rank athletes. I have been using a technique on starts and turns in the butterfly event, that involves the swimmers kicking on their sides (fish kick), rather than on their front (dolphin kick). The thesis is that more power can be generated with the fish kick as a result of a more advantageous interaction between the counter-rotational vorticies of the forward and backward foil movements. During a dolphin kick, the interaction between the vorticies is disrupted because of the distortion of the vorticies with the bottom of the pool and surface of the water. Can anyone assist with evaluating this thesis and estimations of magnitude using CFD. Reference: "Robo Tuna", Scientific American, Triantafllou, March, 1995.