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Go on Andy, take a great big chunk out and see what happens
Interesting, I'll need to add all these photos to the weird collection tooHey guys, I couldn't resist. Howz this for a big chunk cut out? ;-) See below pic....
Interesting, I'll need to add all these photos to the weird collection too
I am afraid though that this last design cannot be really efficient, because you can't really get the blade into the right angle of attack in the upward and downward kick. The angle seem to be pretty constant and the blade seems to bend only from the foot-pocket to the extremity, hence in practically 90 degrees to the swimming direction (well, it is little bit less due to the angle of the demi-lune - around 60 degrees at the extremity). On my mind, it does not really help with the propulsion a lot.
In our club, we have an university professor working in department of physics of fluids. We already spoke that he could let his students research some freediving fins related topics, we just did not get yet to define the jobs. Modeling and comparing different shapes of fins like these ones may be one possibility.
Tails need angle of attack in order to create any forwards thrust. Humans wearing flat blades have 0 degrees angle of attack. In order to get any angle, a blade needs to flex. Otherwise you'd just be pushing a flat surface sideways through the water, for no benefit....
Send me please a PM, or email to ivo at apnea.czHey, Trux... talk to me before you add this photo to your collection; I'd like to be able to give you the correct information. Thanks.
The club is Cyrnéa Lyon, and the University is Université Claude-Bernard Lyon 1, Laboratoire de Méchanique des Fluids et d'AcoustiqueCool. What club is this? And what university? Where?
The very simple reason is speed (power to drag). Sailfish and Wahoo are usually considered the fastest fish and at 30-40 knots they have a P/D ratio about ten times the best human. If you'd really like to feel puny calculate the speed required to lift the centre of gravity 3-4 meters out of the water in a dolphin show and then consider that no human has been able to get to 1M or even clear of the water.