hats off to the raggies!

[MapisM]

And moboers learn that it isn't "just like driving a car" ?

LOL, obviously Daka struck a nerve with his comment...
What you're saying is something which equally affects stinkies and raggies, in my experience.

 

[hlb]

You're right, AoA and Newton do in genera contribute to sail boats. The numbers are very complex though

For Newton AoA to work you need an external force. =The props on a mobo or the tow-rope on the water ski. The work done by the foil (force x distance, where force is the drag and the compression load on the fluid below and in front of the foil) is equal to the work done by the engine (totally ignoring friction and all parasitic losses, of course)

With a sailboat there generally is no such "engine" to do any work on the foil. But there is the wind, and that is the engine. Alternatively, if you think of motion as all relative, you can think of the air as stationary and the keel as pushing the boat into the wind like a massive midships bow thruster/propeller. The maths is the same however you choose to do it. So that gives you much Newtonian lift force. Another way to visualise it is that the keel and hull make a resistance like the string of a kite, and that causes the wind to create Newtonian forces on the sail. To state the obvious, a kite flies almost entirely due to Newton, not Bernouille; it is a copycat of a waterski.

Of course on a sailboat there is Bernouille force too. The Newton/Bernouille mix depends on the point of sailing so you cannot generalise. Broad reaching is mostly Newton; closehauled has much more Bernouille. The maths is very complex and beyond me now (though not at university!)

Very crudely, iirc, on a commercial plane the bernouille/Newton mix is in the order of 25-75 in steady state no-flaps flight

Yep and I can now tell exactly why they train pilots my way and why I used the illustration to our friend.

Else we'd all have been here a bloody month.

 

[MapisM]

Else we'd all have been here a bloody month.

Well H, we've actually been here discussing this and other even more trivial matters for years rather than just a month, if you think about it...

 

[hlb]

Well H, we've actually been here discussing this and other even more trivial matters for years rather than just a month, if you think about it...

Yes, but in the past, we had a better class of trivia.

Hence I mainly stay in the lounge these days.

Ok I glance at mobo, maybe once a day. But there's never anything here.

No adventures, no mishaps and no exploding bogs.

On top of that, me legs err knackered and me back doesn't work, so that's why I fell over and broke me collar bone, so me arm is in a sling, so I have to stop, to go round sharp bends and I get shouted at going round magic roundabouts.

Never mind the airyplanes, yachts mostly get sucked along. That's why the old square riggers could only go down wind, because Pythagerous had not been invented and he was rubbish at sucking anyway.

Going down bonk, you get the sails open as much as you can, best is one on each side, which they call goose winging.

Goose winging can be fun or bloody painful, as if you get it wrong or the wind changes, you get a sore head, which is called jibing.

Jibing is when the wind decides it wants to go the other way round, so it sends the boom into your head, to see if you're still awake.

Mostly your not, so both boat and wind has now taught you who was really in charge in the first place.

Here Eadith the first lesson.

 

[MapisM]

No adventures, no mishaps and no exploding bogs.

Yep, we definitely miss all that.
Gosh, can't believe I just said I'm missing an exploding bog...

Sorry to hear that your health is not improving. All the very best anyway!