Sail in the sunshine
Movie Score: four / five
what about when a boat loses its keel (on a reef or some such), they still
sail … forwards! albeit less efficiently and somewhat dangerously, they
still ‘work’ from a momentum perspective. their forward moment is still
greater than the leeway, even without a keel.
this kind of ‘lift’ theory of aerodynamics has (in the past decade) been
quite disputed in the field of aerodynamics anyway, as many experiments
with airfoil (wing) designs which should not create any lift according to
this theory – do!
so this is not the whole story. it may play a part (maybe even a large
part) but its not a complete explanation of whats going on.
7:47 watch the two sailboats and the motorboat, above the sailboat with the
red sail – almost a bonus clip with a sail disaster, and a lesion by
itself; How to NOT maneuver a boat in crowded situations.
Scientists are terrible at explaining things lol
wishy washy kinda
a luffing sail and a stall on an airplane wing are not aerodynamically
Hey guys. Here’s a neat video explaining the physics of sailing into the
wind (old square sail ships couldn’t do this)
That was fun.
While it is true that the acceleration of the fluid across the curved
surface of a wing results in a lower pressure on that surface, this is NOT
the whole story. It is by far the influence of the increased pressure
along the BOTTOM of the wing created by the turning of the flow stream
encountering the surface of the wing presented by the “angle of attack” of
the wing that generates a lot of the lift. Otherwise, a plane could NOT
fly upside down. A flat wing generates lift with the proper angle of
This is an OLD explanation and is correct as far as it goes, but it is a
vastly incomplete explanation. More modern ‘rotational flow’ theory is a
By drawing a control volume around the wing and calculating the change in
the momentum of the flow field, the actual lift and form drag forces can be
calculated. This of course does not calculate the frictional drag. If you
do this for a wing where the under surface of the wing is parallel with the
flow, you will generate a great deal LESS lift than when the wing has an
angle of attack.
“Square rigged ships only went in one basic direction – with the wind”
PARDON?! Clearly, this statement is false. What did they do if the wind
changed, or if they had to return home against the trade winds?
In fact, square riggers, while not as efficient to wind as a modern sailing
boat, could sail at a reasonably close angle to the wind.
lol lucky you’re doing it somewhere warm and not somewhere freezing like
Hamworthy (Poole, UK)
Lift (in sails as in wings) is generated according to Newton’s 3rd:
the most idiotic video ive ever seen!(from the eyes of a sailor).
1:52 I was dying that that jib sheet wasn’t being pulled!
“A luffing sail is not the equivalent of stall on an aircraft”, per minute
7:40, it would be an over-trimmed sail.
Hard to take this seriously when the first thing they say is completely
wrong. Square-rigged ships can most certainly sail into the wind. It’s true
that they can’t lie as close to the wind as a fore-and-aft rigged ship, but
they can tack.There’s no way Magellan, Drake etc. could have made it around
the world in ships that only sailed with the wind. Getting around Cape Horn
from east to west is impossible if you can’t sail your ship into the wind.
I’ve always been so fascinated on how sailing ship works!!
Hey guys, just a note about why lift happens, this guy is chatting bull.
Bernoullis law doesnt apply in the case of a wing (or sail). For his law to
apply, certain assumptions must be made. firstly that the fluid has zero
viscosity, but as we can see, the fluid ‘sticks’ to the shape of the wing,
which is a viscous effect. secondly, that it is a steady flow. which as
said in the video, it is not. Finally, Bernoullis theorem only applies to a
single flow, once you talk about flows above and below a wing, its moot.
While Bernoullis can describe some of what is happening, the fundamental
law behind lift is newtons 3rd. watch the flow as it comes off the wing,
its at a different angle, meaning a force was imparted on the air by the
wing, and thus vice versa
(im an aerospace engineering student and even people in the aero business
get this wrong (including the most of the internet), and this isnt coming
from me, this is coming from Dr Iain Dupere at Manchester University)
When you blow on that piece of paper, does the Coanda effect help create
that lift ?
Your model desperately l lacks sail trim. Move your jib cars back and for
the love of god, tighten your outhaul!
How do you guys (the sailing school) get away with completely inadequate
safety equipment for students? And then comically prodcast it to the whole
world via youtube. You should be closed down by the US authorities. Boyancy
aids. are not suitable life savers for offshore yacht sailing!! Inshore
dinghysailing with supervision maybe……….
I always thought that if I were to travel back thru time, this would be one
of the most valuable bits of knowledge to have.
SQUARE RIGGERS CAN SAIL TO 90 DEGREEZ FROM FROM DA WIND
it’s simpler to just figure out a workable route and let the sail dictate
the angle of approach, turn away from the wind until the sail starts
catching and let the wind push/pull you along. always look to your sail for
information, it’ll tell you how it wants to work.
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