abr wrote:caustic wrote:http://riversportokc.org/row/about/rowing-terms
conveniently, this shows a great photo of an oar patently showing a lack of directional flow across it's convex surface. No linear flow = no lift. You'll notice that you can see that not only is water moving around each side, but also over the top! And although we can't see it, it is also flowing up from the bottom. Flow that is conducive towards a lifting force cannot all move together from all the edges like that.
I'm not going to try to get at all the different things you've said that don't make any sense, but how can you possibly think it helps your case to get people to look at a photo of an oar that appears to be exactly perpendicular to the direction of travel, at the precise place where the proponents of lift agree that there is no lift?!
Try to find the same kind of shot, but near the catch or finish.
Tell you what, you list which things don't make sense, and I'll clarify.
Not a problem. I can get the oar to make a similar pattern at any angle, because I've already done it. You can to, actually. Square your blade in the water, at any angle you like, and just do a short pull through - a few inches is all you really need to move some water. You'll clearly see that two vortices rotating in opposite directions, form on the convex side of the blade. You cannot have any kind of net water flow across the blade that can generate lift when you have vortices forming on both the leading and[i]trailing edge of the blade.
That photo shows three things that have to have happened well before that angle - 1)the outer vortex, 2)the inner vortex, and 3)the large depression. None of those form instantly the blade hits the "stall" phase of the stroke. Thats just where they are [i]maximal. They exist for almost the entire duration of the stroke. You can form them at any angle, at any phase, and with almost any pressure on the blade - their magnitude will be different, but they will always show up.