I have been studying videos of swimmers and find what was once called the "S" stroke has almost disappeard.
I have noticed that flyers use it. But crawl swimmers have modified it so much that it is almost gone.
Has it been replaced completely or was it an optical illusion? Did underwater film show us it did not exist.
We can talk physics, hydrodynamics, insertion without bubbles, low pressure , highpressure, etc. But when it comes down to swimming you have to have a true feeling for the water. We are not a boat with one drive force. We have many moving parts and it still is going to be trial and error.
We are definitely in a situation where fluid mechanics has not caught up with human propulsion in the water. I think coaches throwing around half-cocked theories of propulsion tends to slow down the effort to explain what is going on. In all the hoorah about lift forces for propulsion I saw exactly one study with numbers on it referenced. For shed vortices, none.
Ernie Maglischo in swimming fastest references some computational fluid dynamics studies showing that a slight side to side motion creates more propulsion, but not because of lift, it actually improves the drag forces on the hand as you pull.
If we are to get anywhere, for now it looks like the computational fluid dynamics will help us. But these things are fiendishly difficult to solve and take real horsepower. The ones listed here (projects.seas.gwu.edu/.../MAIN.htm) take 20 days or so to solve.
So I think we are left trying to feel the water and get a better purchase on it, we are also left having to discuss with no real science to back us up.
We can talk physics, hydrodynamics, insertion without bubbles, low pressure , highpressure, etc. But when it comes down to swimming you have to have a true feeling for the water. We are not a boat with one drive force. We have many moving parts and it still is going to be trial and error.
We are definitely in a situation where fluid mechanics has not caught up with human propulsion in the water. I think coaches throwing around half-cocked theories of propulsion tends to slow down the effort to explain what is going on. In all the hoorah about lift forces for propulsion I saw exactly one study with numbers on it referenced. For shed vortices, none.
Ernie Maglischo in swimming fastest references some computational fluid dynamics studies showing that a slight side to side motion creates more propulsion, but not because of lift, it actually improves the drag forces on the hand as you pull.
If we are to get anywhere, for now it looks like the computational fluid dynamics will help us. But these things are fiendishly difficult to solve and take real horsepower. The ones listed here (projects.seas.gwu.edu/.../MAIN.htm) take 20 days or so to solve.
So I think we are left trying to feel the water and get a better purchase on it, we are also left having to discuss with no real science to back us up.
