Exploring another idea

Sorry. Yes it was a quick search to clarify the term as I had never heard it before. I'm glad you disagree with a lot of what is said.

 

I have read somewhere that Michael Phelps has outstreched arms longer by 2" than most of us by proportion. So he has a slight advantage of greater propulsion.

He also has slim hips, reducing form drag which gives him an edge over most swimmers.

 

Correct me if I am wrong, I will be happy to be educated. These are small bits of information and unsubstantiated arguments I hear.

That butterfly stroke is the most inefficient and slowest of swim style as most of the time the swimmer is above water creating Wave Drag. Swimmers gets tired easily.

That breast stroke is the most efficient but not the fastest. The body is mostly underwater and only the neck is in the waterplane. Deeply submerged bodies,Small Waterplane Area?

That the freestyle is the fastest, a good combination of underwater resistance and wavemaking resistance plus the fact that the arm (propulsion) is above water (venting) half of the time in the return stroke. Sounds like Surface Piercing propeller.

 

I used Phelps as a recognizable reference. It's pretty much standard practice now for all competitive swimmers.

Yes, these physical characteristics are true of Michael Phelps. So, you would think that with such a powerful wing span that he would be faster on the surface and that he would want to start his stroke as soon as possible after first entering the water or coming off the wall. But instead he stays underwater for as long as "legally" possible which is 10 meters, I think. Swimmers were taking such advantage of this that they had to limit the length they could stay underwater.

Ryan Lochte is in fact better at it than Phelps. It's really about streamline your body and gliding, not unlike seals or Dolphins. When underwater you can feel how easily driven this shape is. How easy would it be to propel a torpedo styled bulb that has a minimal amount of form drag?

 

http://youtu.be/xZSUQwfg6ZU

An example of Ryan Lochte underwater. 20.8 seconds is faster than the world 50m freestyle record. And that's human propulsion...

 

http://youtu.be/QxrYJf48s-4

This guy was disqualified but it gives you an idea of how much faster you can be underwater.

 

http://youtu.be/HROUjQcVVjA

Ok, lastly, a free diver practicing for a record attempt. Notice how little it takes to move 25 meters. He begins to slow and it is apparent that the human body is not designed perfectly for this. But, hey, not bad!

 

You mean standard practice to have long arms?

 

The insect is not "floating on air pockets".

 

Relying on surface tension of water.

 

Ok. I just thought it looked a little like my sketch. Not worthy of any focus.

 

I gave some consideration to to using a buoyancy bulb on a foiling kayak to lower the thrust and power required to a level I could sustain. My recollection is that it should work -it should result in a boat that would go faster than a long skinny conventional kayak. My calculation was far from scientific. I used the volume and surface area of an ellipse rotated and assumed the drag/surface area was the same as the foil and wave loss of zero. These assumptions seem reasonable for human powered low speeds but for a sail powered craft I think something better would be required.

If you are looking for the next wild idea with a buoyancy bulb how about a sailboat that has a buoyancy bulb that can move from one side of a wing to the other to provide righting moment? It's like a canting keel but in reverse. Sound silly? Well, which do you think goes better with a horizontal lifting foil a lead bulb or a buoyancy bulb?

 

Not a "silly" idea at all. I hadn't thought of it. I prefer it when someone risks seeming silly and presents an idea, however proposterous, to someone contributing nothing but silly vacuous critiques.

 

Rick Willoughby explored using submerged bouyancy with his V8 pedal boat here:

http://www.rickwill.bigpondhosting.com/V8.htm

 

Nice bulb but the aft end should be skinnier and pointy. I think he could get rid of the big beams and floats if he just had some wings on the bulb and some skimmers linked to trim tabs for dynamic stability. I think he would have realized a much higher speed if he didn't have three crude floats dragging in the water making waves.