OK this sounds like a stupid question but someone at the pool told me that my hand needs to be open with my fingers apart when I swim. i normally cup it which is what I thought was the best way. Today I tried my fingers together and my thumb out a little bit from the hand.
The cupped hand seemed best but what do the experts say?
Originally posted by LindsayNB
As a thought experiment one can image a paddleboat with paddle wheels moving at a constant velocity. The boat can move forward without requiring the paddles to accelerate.
As long as we are being picky :D the wheel may be rotating at a constant rate, but the blades are always accelerating. Any object moving in a curved motion has to be accelerated (otherwise it would be moving in a straight line).
Aaaaannndddd back to our regular subject... ;)
Found this article with a Google search:
Analysis of Swimming Techniques using Vortex Traces
...which is probably more than most people want to read. :eek: I think the passage that is most relevant is quoted next. The idea of pushing a handful of water backwards (like a jet) is somewhat misleading. Paddling may be easier to model and comprehend, but the evidence is that the 2nd method (involving a vortex) is more energy-efficient.
Principles of propulsion as known from the realm of aquatic animals are closely related to the way how the counter bearing is produced (Webb, 1988):
via use of pressure differences, e.g. paddling of Ducks;
via use of vortex - induced momentum in conjunction with acceleration reaction, e.g. whip lash like movement of 'profiled' flukes or fins of Dolphins, Sharks or true Seals;
via use of hydrodynamic lift, e.g. flying through the water of Mantas, Penguins. The difference in producing the counter bearing is related to the different morphological properties of the animals.
Originally posted by LindsayNB
As a thought experiment one can image a paddleboat with paddle wheels moving at a constant velocity. The boat can move forward without requiring the paddles to accelerate.
As long as we are being picky :D the wheel may be rotating at a constant rate, but the blades are always accelerating. Any object moving in a curved motion has to be accelerated (otherwise it would be moving in a straight line).
Aaaaannndddd back to our regular subject... ;)
Found this article with a Google search:
Analysis of Swimming Techniques using Vortex Traces
...which is probably more than most people want to read. :eek: I think the passage that is most relevant is quoted next. The idea of pushing a handful of water backwards (like a jet) is somewhat misleading. Paddling may be easier to model and comprehend, but the evidence is that the 2nd method (involving a vortex) is more energy-efficient.
Principles of propulsion as known from the realm of aquatic animals are closely related to the way how the counter bearing is produced (Webb, 1988):
via use of pressure differences, e.g. paddling of Ducks;
via use of vortex - induced momentum in conjunction with acceleration reaction, e.g. whip lash like movement of 'profiled' flukes or fins of Dolphins, Sharks or true Seals;
via use of hydrodynamic lift, e.g. flying through the water of Mantas, Penguins. The difference in producing the counter bearing is related to the different morphological properties of the animals.
