Paddle angle changes during the duration
of an axle or post as the momentum slows… So that is not a fixed position of the “fulcrum ray”. What is generally agreed on is that an open angle too early stops the boat.
I have often wondered why the prying sideslip involves moving the paddle forward as the boat slows and the drawing one does not.
ray target
I can not dispute it since it takes quite a while to figure out.
Here is why-
- Force generated by paddle includes lift and drag components, they are both a function of foil shape, angle of attack, speed of movement.
- Since ratios of drag and lift components vary, the location in relationship to CLR will vary as well. I find it a rather entertaining academic exercise, and will, probably, do numerics at some point. Probably will assume the paddle to be flat for simplicity’s sake
- CLR definitely moves. Here is how we demonstrate it in a kayak: get on the water, balance your boat so it is stable at beam wind. Get a little forward speed, bow goes into the wind, get a little backward speed, stern goes into the wind. Since the rest of variables doesn’t change - explanation of windcocking can be achieved through the movement of fulcrum point.
So yes, it might be true that the imaginary arrow points towards the CLR, but I don’t see a way to prove it.
Theory won’t instruct less adept
paddlers any more than theory of bipedal balance would instruct Stephen Maturin how to walk on the rolling deck of the Surprise. Maturin’s problem was too much time spent below, reading and playing the cello.
There isn’t time, even in tedious ACA instruction, to go through theory. One must quickly demonstrate for the monkeys, and then it’s monkey see, monkey do. Understanding of motor/skills learning was developed by psychologists, not physicists.
COLR & Ship generated sideways current
– Last Updated: Dec-31-12 7:50 AM EST –
Dear all,
You may be interested by these:
http://www.youtube.com/watch?v=3Y0G2G5IpEo
at 7:20
http://www.youtube.com/watch?v=jZyHdWJkOD0
and
http://www.youtube.com/watch?v=boOb5vB8jP4
Regards
clr change with velocity
i assume clr will change with canoe speed, since the shape of waterline will alter depending on many factors such as in weight distribution, wind and current (and speed). i try to visualize a top view of the water line on lets say a motionless sailing canoe, and then the waterline goin on wind and off wind. they all will have diferent shapes, therefore, diferent CLR. also concerning the speed, on a slowing boat, natural forces will push bow down, CLR moves forward, speeding up will pull the bow up, CLR moves back.
this is my 2cents