 
Boat and Wind Basics
Sailing is Not a Complicated Sport by Michael Sanford
It seems obvious how a sailboat sails downwind: It is pushed
along by the wind in its sails. Less obvious is how it can
sail upwind or how some sailboats can sail faster than the
wind.
Sir Isaac Newton formulated three basic laws that pertain
to the motions and accelerations of all objects.
Let us have a look at the third law: For any force exerted
on an object, an equal but opposite force must be exerted
by that object onto whatever exerted the force. A direct consequence
of this law is the conservation of momentum (Momentum equals
mass times velocity). The conservation of momentum tells us
that if the velocity of one thing is somehow changed (in either
magnitude or direction) that the velocity of something else
must also change accordingly. Moreover, a large change in
velocity of a light object can be balanced by a small change
in velocity of a massive object. This is, of course, how a
sailboat sails. Because of its large sail area, a sailboat
can change the velocity of a huge amount of air in a small
amount of direction or speed. The change of velocity that
the sailboat imparts to the air hitting her sails is mainly
a change in the direction in which the air is moving. So a
sailboat can experience a large driving force even when she
is sailing against the wind. In the real world, there are
two forces. One is the wind pushing on the sail when it is
changing direction. The air traveling over the leeward surface
of the cambered sail creates the second force. It has to travel
a longer way to reach the end of the sail (the leech), and
as a consequence goes faster. This is causing a pressure differential
in accordance with Bernoulli's principle. (More speed gives
less pressure and less speed gives more pressure).
So a sailboat can sail upwind with the addition of these
two forces. But remember that the force created by the depression
is four times bigger that the one created by pushing the air
sideways. A fluid flow exerts a force upon an object in a
direction perpendicular to the uninterrupted flow of that
fluid. As a result, a lift is generated. But there is also
creation of a drag that is a force acting in the direction
of the fluid.Because lift and drag are defined as being perpendicular
to one another, any force acting on a sail can, using trigonometry,
be divided into a lift component and a drag component. By
separating the force into these two components, we can study
the relationships between lift, drag, the shape of the sail,
and the angle between the sail and the airflow( AOA or Angle
Of Attack with the Greek letter)
Sailing is not a complicated sport. Anyone can do it and
enjoy it. Spend time on the water You just need to take a
little time on the water. Trying and collecting experience
is one of the best way to learn. I am sure you will have a
great time on the water. You can start just by yourself. Plenty
of sailors started buying, renting, borrowing or otherwise
obtaining a boat for their first sail without any knowledge.
Let me say that you have to take care because it could be
hazardous to your health. Get the Right Boat For a child,
learning to sail in a dinghy seems natural. For an adult,
it is not so simple. You react less by instinct and fear to
go on this unstable machine could surface. For this reason,
many people opt for a larger, seemingly more forgiving big
boat to learn on. It is another way, but they miss out on
a pure form of sailing not experienced in larger boats. Is
it Dangerous? Which danger could threaten you on a small sailing
boat? You could tip over. It is called "Capsize".
Capsizing and learning to right your boat again are all part
of the learning process and could be fun. With the fear of
capsize behind you, you will be able to concentrate wholly
on sailing maneuvers instead of constantly worrying about
getting wet. Don't wait and Jump Remember, you told everyone
that you would like to become a sailor and go across oceans...
Well, it's time to make good on that. At first, gauge how
you feel about the water. During your last summer vacation,
did you jump right in the water or did you cautiously wade
in? Okay, I agree it could depend of the weather and the temperature
of the water. But if you're a jumper, you can stop reading
here. Just take a day off from the office, buy or rent a boat,
or ask an old friend sailor to come with you, and get out
of here! If you're still with me, then you're a wader. Don't
worry. I am not a jumper too, and I sailed during the last
40 years having fun. It is difficult for me to take the decision
to go, but if I fall, by accident,in the (cold) water, it
is not such a big problem for me. The more I think about,
the less I go... Have no fear. Nobody is going to splash you.
Let's start with dipping our toes into the water. The way
to do that with sailing is to go out and buy a few books about
the sport. Stay away from anything boring, technical, or overly
historical. You need an easy book, with a lot of drawings,
and nice to read. Lobbying, Lobbying Now let's go to a more
serious work. Figure out a way to catch an invitation onto
a sailboat. The important thing is to get sailing. You can
pay to go on a sailing boat with skipper, or twist a friend's
arm to be invited aboard his next sail. I don't care the method.
You need to go on the water. As a good info, it is very rare
to be sick on small boats. You are outside, in the wind, all
thing concurring to have you feeling well. Just take care
not to do a race with a crazy guy who will cure you of sailing.
You have to start with a mellow sailing day. Take a Course
It's time to move on to the second step. Find an adult sailing
course and sign up for it. Personally, I would recommend taking
your first lessons in a small sailing boat, a dinghy. For
sailing courses they are designed for beginners. They will
give you an immediate response to any shifts in the variables
that affect sailing (weight, wind, waves, and weather). If
your wife (or your husband, boyfriend or girlfriend) wants
to learn sailing too, take separate classes. It's difficult
enough to learn a new sport without having your partner watching
over your shoulder at every step of the way. It will be time
later to sail (and should the occasion arise, to fight) all
together, as an old couple, on the same boat.
For more information on sailing please visit the sailing
resource center at http://sailing-advice-guide.info/ |
