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> "As a research aerodynamicist, I was dumbfounded when I first started reading the sailing literature as a beginning sailor and saw what a confused state sail

by Isamu 10y ago

> "As a research aerodynamicist, I was dumbfounded when I first started reading the sailing literature as a beginning sailor and saw what a confused state sail theory was in. Even the basic explanations of how a sail generates lift were wrong. This I could understand, since even the popular aviation books were wrong in their attempts to explain lift. It is difficult to explain the generation of lift for laymen. The simplifications devised in attempts to do this seemed logical but usually turned out to be wrong" He has a very readable section where he goes through the wrong explanations (e.g. Bernoulli effect) and explains why they are incorrect, and then corrects them with helpful diagrams.

deleted 10y ago
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mbrookes 10y ago
I'm somewhat disconcerted. There was an article on HN yesterday [1] in which one of the replies to the top comment about AG Bell's attempts at flight said: "The difference is that Bell didn't understand aerodynamics and didn't seem to do a thing about it." That reminded me about an article I'd read some time back that suggested that even modern aviation experts don't correctly understand lift. Today, that article is on the front page of HN. [1]1 https://news.ycombinator.com/item?id=13817912 https://news.ycombinator.com/item?id=13817912
sandworm101 10y ago
When i was a kid i had a windsurfer, one of the first "no nose" boards that could barely keep itself afloat. You have to keep these moving if you want to stay up. And they like to move. Comming from racing lasers and hobies, one day I attached a telltale atop the mast. The wind is 20knots, im tacking slightly upwind at 25knots (call it 70* across the wind) and the telltale is pointing strait back. Wtf. So i put one on my hand and hold it away from the sail... still strait back. How it is possible for me to be, from my perspective, racing directly into a headwind. I get the basic physics, but as a teenager on a board it's pretty much magic. If you really want perspective on sail and wing theory, forget the ropes and booms. Get an airfoil you can hold in your own hands. Feel the effects yourself. Be warned, windsurfing has an evil learning curve imho probably moreso than kiteboarding.

by Isamu 10y ago

deleted 10y ago

[deleted]

mbrookes 10y ago

I'm somewhat disconcerted. There was an article on HN yesterday [1] in which one of the replies to the top comment about AG Bell's attempts at flight said: "The difference is that Bell didn't understand aerodynamics and didn't seem to do a thing about it." That reminded me about an article I'd read some time back that suggested that even modern aviation experts don't correctly understand lift. Today, that article is on the front page of HN. [1]1 https://news.ycombinator.com/item?id=13817912 https://news.ycombinator.com/item?id=13817912

sandworm101 10y ago

When i was a kid i had a windsurfer, one of the first "no nose" boards that could barely keep itself afloat. You have to keep these moving if you want to stay up. And they like to move. Comming from racing lasers and hobies, one day I attached a telltale atop the mast. The wind is 20knots, im tacking slightly upwind at 25knots (call it 70* across the wind) and the telltale is pointing strait back. Wtf. So i put one on my hand and hold it away from the sail... still strait back. How it is possible for me to be, from my perspective, racing directly into a headwind. I get the basic physics, but as a teenager on a board it's pretty much magic. If you really want perspective on sail and wing theory, forget the ropes and booms. Get an airfoil you can hold in your own hands. Feel the effects yourself. Be warned, windsurfing has an evil learning curve imho probably moreso than kiteboarding.